fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66 static int ext4_commit_super(struct super_block *sb, int sync);
  67 static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                         struct ext4_super_block *es);
  69 static void ext4_clear_journal_err(struct super_block *sb,
  70                                    struct ext4_super_block *es);
  71 static int ext4_sync_fs(struct super_block *sb, int wait);
  72 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  74 static int ext4_unfreeze(struct super_block *sb);
  75 static int ext4_freeze(struct super_block *sb);
  76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  77                        const char *dev_name, void *data);
  78 static inline int ext2_feature_set_ok(struct super_block *sb);
  79 static inline int ext3_feature_set_ok(struct super_block *sb);
  80 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  81 static void ext4_destroy_lazyinit_thread(void);
  82 static void ext4_unregister_li_request(struct super_block *sb);
  83 static void ext4_clear_request_list(void);
  84
  85 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  86 static struct file_system_type ext2_fs_type = {
  87         .owner          = THIS_MODULE,
  88         .name           = "ext2",
  89         .mount          = ext4_mount,
  90         .kill_sb        = kill_block_super,
  91         .fs_flags       = FS_REQUIRES_DEV,
  92 };
  93 MODULE_ALIAS_FS("ext2");
  94 MODULE_ALIAS("ext2");
  95 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  96 #else
  97 #define IS_EXT2_SB(sb) (0)
  98 #endif
  99
 100
 101 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 102 static struct file_system_type ext3_fs_type = {
 103         .owner          = THIS_MODULE,
 104         .name           = "ext3",
 105         .mount          = ext4_mount,
 106         .kill_sb        = kill_block_super,
 107         .fs_flags       = FS_REQUIRES_DEV,
 108 };
 109 MODULE_ALIAS_FS("ext3");
 110 MODULE_ALIAS("ext3");
 111 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 112 #else
 113 #define IS_EXT3_SB(sb) (0)
 114 #endif
 115
 116 static int ext4_verify_csum_type(struct super_block *sb,
 117                                  struct ext4_super_block *es)
 118 {
 119         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 120                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 121                 return 1;
 122
 123         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 124 }
 125
 126 static __le32 ext4_superblock_csum(struct super_block *sb,
 127                                    struct ext4_super_block *es)
 128 {
 129         struct ext4_sb_info *sbi = EXT4_SB(sb);
 130         int offset = offsetof(struct ext4_super_block, s_checksum);
 131         __u32 csum;
 132
 133         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 134
 135         return cpu_to_le32(csum);
 136 }
 137
 138 int ext4_superblock_csum_verify(struct super_block *sb,
 139                                 struct ext4_super_block *es)
 140 {
 141         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 142                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 143                 return 1;
 144
 145         return es->s_checksum == ext4_superblock_csum(sb, es);
 146 }
 147
 148 void ext4_superblock_csum_set(struct super_block *sb)
 149 {
 150         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 151
 152         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 153                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 154                 return;
 155
 156         es->s_checksum = ext4_superblock_csum(sb, es);
 157 }
 158
 159 void *ext4_kvmalloc(size_t size, gfp_t flags)
 160 {
 161         void *ret;
 162
 163         ret = kmalloc(size, flags);
 164         if (!ret)
 165                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 166         return ret;
 167 }
 168
 169 void *ext4_kvzalloc(size_t size, gfp_t flags)
 170 {
 171         void *ret;
 172
 173         ret = kzalloc(size, flags);
 174         if (!ret)
 175                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 176         return ret;
 177 }
 178
 179 void ext4_kvfree(void *ptr)
 180 {
 181         if (is_vmalloc_addr(ptr))
 182                 vfree(ptr);
 183         else
 184                 kfree(ptr);
 185
 186 }
 187
 188 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 189                                struct ext4_group_desc *bg)
 190 {
 191         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 192                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 193                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 194 }
 195
 196 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 197                                struct ext4_group_desc *bg)
 198 {
 199         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 200                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 201                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 202 }
 203
 204 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 205                               struct ext4_group_desc *bg)
 206 {
 207         return le32_to_cpu(bg->bg_inode_table_lo) |
 208                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 209                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 210 }
 211
 212 __u32 ext4_free_group_clusters(struct super_block *sb,
 213                                struct ext4_group_desc *bg)
 214 {
 215         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 216                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 217                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 218 }
 219
 220 __u32 ext4_free_inodes_count(struct super_block *sb,
 221                               struct ext4_group_desc *bg)
 222 {
 223         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 224                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 225                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 226 }
 227
 228 __u32 ext4_used_dirs_count(struct super_block *sb,
 229                               struct ext4_group_desc *bg)
 230 {
 231         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 232                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 233                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 234 }
 235
 236 __u32 ext4_itable_unused_count(struct super_block *sb,
 237                               struct ext4_group_desc *bg)
 238 {
 239         return le16_to_cpu(bg->bg_itable_unused_lo) |
 240                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 241                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 242 }
 243
 244 void ext4_block_bitmap_set(struct super_block *sb,
 245                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 246 {
 247         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 248         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 249                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 250 }
 251
 252 void ext4_inode_bitmap_set(struct super_block *sb,
 253                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 254 {
 255         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 256         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 257                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 258 }
 259
 260 void ext4_inode_table_set(struct super_block *sb,
 261                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 262 {
 263         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 264         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 265                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 266 }
 267
 268 void ext4_free_group_clusters_set(struct super_block *sb,
 269                                   struct ext4_group_desc *bg, __u32 count)
 270 {
 271         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 272         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 273                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 274 }
 275
 276 void ext4_free_inodes_set(struct super_block *sb,
 277                           struct ext4_group_desc *bg, __u32 count)
 278 {
 279         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 280         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 281                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 282 }
 283
 284 void ext4_used_dirs_set(struct super_block *sb,
 285                           struct ext4_group_desc *bg, __u32 count)
 286 {
 287         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 288         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 289                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 290 }
 291
 292 void ext4_itable_unused_set(struct super_block *sb,
 293                           struct ext4_group_desc *bg, __u32 count)
 294 {
 295         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 296         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 297                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 298 }
 299
 300
 301 static void __save_error_info(struct super_block *sb, const char *func,
 302                             unsigned int line)
 303 {
 304         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 305
 306         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 307         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 308         es->s_last_error_time = cpu_to_le32(get_seconds());
 309         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 310         es->s_last_error_line = cpu_to_le32(line);
 311         if (!es->s_first_error_time) {
 312                 es->s_first_error_time = es->s_last_error_time;
 313                 strncpy(es->s_first_error_func, func,
 314                         sizeof(es->s_first_error_func));
 315                 es->s_first_error_line = cpu_to_le32(line);
 316                 es->s_first_error_ino = es->s_last_error_ino;
 317                 es->s_first_error_block = es->s_last_error_block;
 318         }
 319         /*
 320          * Start the daily error reporting function if it hasn't been
 321          * started already
 322          */
 323         if (!es->s_error_count)
 324                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 325         le32_add_cpu(&es->s_error_count, 1);
 326 }
 327
 328 static void save_error_info(struct super_block *sb, const char *func,
 329                             unsigned int line)
 330 {
 331         __save_error_info(sb, func, line);
 332         ext4_commit_super(sb, 1);
 333 }
 334
 335 /*
 336  * The del_gendisk() function uninitializes the disk-specific data
 337  * structures, including the bdi structure, without telling anyone
 338  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 339  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 340  * This is a kludge to prevent these oops until we can put in a proper
 341  * hook in del_gendisk() to inform the VFS and file system layers.
 342  */
 343 static int block_device_ejected(struct super_block *sb)
 344 {
 345         struct inode *bd_inode = sb->s_bdev->bd_inode;
 346         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 347
 348         return bdi->dev == NULL;
 349 }
 350
 351 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 352 {
 353         struct super_block              *sb = journal->j_private;
 354         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 355         int                             error = is_journal_aborted(journal);
 356         struct ext4_journal_cb_entry    *jce, *tmp;
 357
 358         spin_lock(&sbi->s_md_lock);
 359         list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
 360                 list_del_init(&jce->jce_list);
 361                 spin_unlock(&sbi->s_md_lock);
 362                 jce->jce_func(sb, jce, error);
 363                 spin_lock(&sbi->s_md_lock);
 364         }
 365         spin_unlock(&sbi->s_md_lock);
 366 }
 367
 368 /* Deal with the reporting of failure conditions on a filesystem such as
 369  * inconsistencies detected or read IO failures.
 370  *
 371  * On ext2, we can store the error state of the filesystem in the
 372  * superblock.  That is not possible on ext4, because we may have other
 373  * write ordering constraints on the superblock which prevent us from
 374  * writing it out straight away; and given that the journal is about to
 375  * be aborted, we can't rely on the current, or future, transactions to
 376  * write out the superblock safely.
 377  *
 378  * We'll just use the jbd2_journal_abort() error code to record an error in
 379  * the journal instead.  On recovery, the journal will complain about
 380  * that error until we've noted it down and cleared it.
 381  */
 382
 383 static void ext4_handle_error(struct super_block *sb)
 384 {
 385         if (sb->s_flags & MS_RDONLY)
 386                 return;
 387
 388         if (!test_opt(sb, ERRORS_CONT)) {
 389                 journal_t *journal = EXT4_SB(sb)->s_journal;
 390
 391                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 392                 if (journal)
 393                         jbd2_journal_abort(journal, -EIO);
 394         }
 395         if (test_opt(sb, ERRORS_RO)) {
 396                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 397                 sb->s_flags |= MS_RDONLY;
 398         }
 399         if (test_opt(sb, ERRORS_PANIC))
 400                 panic("EXT4-fs (device %s): panic forced after error\n",
 401                         sb->s_id);
 402 }
 403
 404 void __ext4_error(struct super_block *sb, const char *function,
 405                   unsigned int line, const char *fmt, ...)
 406 {
 407         struct va_format vaf;
 408         va_list args;
 409
 410         va_start(args, fmt);
 411         vaf.fmt = fmt;
 412         vaf.va = &args;
 413         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 414                sb->s_id, function, line, current->comm, &vaf);
 415         va_end(args);
 416         save_error_info(sb, function, line);
 417
 418         ext4_handle_error(sb);
 419 }
 420
 421 void ext4_error_inode(struct inode *inode, const char *function,
 422                       unsigned int line, ext4_fsblk_t block,
 423                       const char *fmt, ...)
 424 {
 425         va_list args;
 426         struct va_format vaf;
 427         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 428
 429         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 430         es->s_last_error_block = cpu_to_le64(block);
 431         save_error_info(inode->i_sb, function, line);
 432         va_start(args, fmt);
 433         vaf.fmt = fmt;
 434         vaf.va = &args;
 435         if (block)
 436                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 437                        "inode #%lu: block %llu: comm %s: %pV\n",
 438                        inode->i_sb->s_id, function, line, inode->i_ino,
 439                        block, current->comm, &vaf);
 440         else
 441                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 442                        "inode #%lu: comm %s: %pV\n",
 443                        inode->i_sb->s_id, function, line, inode->i_ino,
 444                        current->comm, &vaf);
 445         va_end(args);
 446
 447         ext4_handle_error(inode->i_sb);
 448 }
 449
 450 void ext4_error_file(struct file *file, const char *function,
 451                      unsigned int line, ext4_fsblk_t block,
 452                      const char *fmt, ...)
 453 {
 454         va_list args;
 455         struct va_format vaf;
 456         struct ext4_super_block *es;
 457         struct inode *inode = file_inode(file);
 458         char pathname[80], *path;
 459
 460         es = EXT4_SB(inode->i_sb)->s_es;
 461         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 462         save_error_info(inode->i_sb, function, line);
 463         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 464         if (IS_ERR(path))
 465                 path = "(unknown)";
 466         va_start(args, fmt);
 467         vaf.fmt = fmt;
 468         vaf.va = &args;
 469         if (block)
 470                 printk(KERN_CRIT
 471                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 472                        "block %llu: comm %s: path %s: %pV\n",
 473                        inode->i_sb->s_id, function, line, inode->i_ino,
 474                        block, current->comm, path, &vaf);
 475         else
 476                 printk(KERN_CRIT
 477                        "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 478                        "comm %s: path %s: %pV\n",
 479                        inode->i_sb->s_id, function, line, inode->i_ino,
 480                        current->comm, path, &vaf);
 481         va_end(args);
 482
 483         ext4_handle_error(inode->i_sb);
 484 }
 485
 486 const char *ext4_decode_error(struct super_block *sb, int errno,
 487                               char nbuf[16])
 488 {
 489         char *errstr = NULL;
 490
 491         switch (errno) {
 492         case -EIO:
 493                 errstr = "IO failure";
 494                 break;
 495         case -ENOMEM:
 496                 errstr = "Out of memory";
 497                 break;
 498         case -EROFS:
 499                 if (!sb || (EXT4_SB(sb)->s_journal &&
 500                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 501                         errstr = "Journal has aborted";
 502                 else
 503                         errstr = "Readonly filesystem";
 504                 break;
 505         default:
 506                 /* If the caller passed in an extra buffer for unknown
 507                  * errors, textualise them now.  Else we just return
 508                  * NULL. */
 509                 if (nbuf) {
 510                         /* Check for truncated error codes... */
 511                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 512                                 errstr = nbuf;
 513                 }
 514                 break;
 515         }
 516
 517         return errstr;
 518 }
 519
 520 /* __ext4_std_error decodes expected errors from journaling functions
 521  * automatically and invokes the appropriate error response.  */
 522
 523 void __ext4_std_error(struct super_block *sb, const char *function,
 524                       unsigned int line, int errno)
 525 {
 526         char nbuf[16];
 527         const char *errstr;
 528
 529         /* Special case: if the error is EROFS, and we're not already
 530          * inside a transaction, then there's really no point in logging
 531          * an error. */
 532         if (errno == -EROFS && journal_current_handle() == NULL &&
 533             (sb->s_flags & MS_RDONLY))
 534                 return;
 535
 536         errstr = ext4_decode_error(sb, errno, nbuf);
 537         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 538                sb->s_id, function, line, errstr);
 539         save_error_info(sb, function, line);
 540
 541         ext4_handle_error(sb);
 542 }
 543
 544 /*
 545  * ext4_abort is a much stronger failure handler than ext4_error.  The
 546  * abort function may be used to deal with unrecoverable failures such
 547  * as journal IO errors or ENOMEM at a critical moment in log management.
 548  *
 549  * We unconditionally force the filesystem into an ABORT|READONLY state,
 550  * unless the error response on the fs has been set to panic in which
 551  * case we take the easy way out and panic immediately.
 552  */
 553
 554 void __ext4_abort(struct super_block *sb, const char *function,
 555                 unsigned int line, const char *fmt, ...)
 556 {
 557         va_list args;
 558
 559         save_error_info(sb, function, line);
 560         va_start(args, fmt);
 561         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 562                function, line);
 563         vprintk(fmt, args);
 564         printk("\n");
 565         va_end(args);
 566
 567         if ((sb->s_flags & MS_RDONLY) == 0) {
 568                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 569                 sb->s_flags |= MS_RDONLY;
 570                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 571                 if (EXT4_SB(sb)->s_journal)
 572                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 573                 save_error_info(sb, function, line);
 574         }
 575         if (test_opt(sb, ERRORS_PANIC))
 576                 panic("EXT4-fs panic from previous error\n");
 577 }
 578
 579 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 580 {
 581         struct va_format vaf;
 582         va_list args;
 583
 584         va_start(args, fmt);
 585         vaf.fmt = fmt;
 586         vaf.va = &args;
 587         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 588         va_end(args);
 589 }
 590
 591 void __ext4_warning(struct super_block *sb, const char *function,
 592                     unsigned int line, const char *fmt, ...)
 593 {
 594         struct va_format vaf;
 595         va_list args;
 596
 597         va_start(args, fmt);
 598         vaf.fmt = fmt;
 599         vaf.va = &args;
 600         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 601                sb->s_id, function, line, &vaf);
 602         va_end(args);
 603 }
 604
 605 void __ext4_grp_locked_error(const char *function, unsigned int line,
 606                              struct super_block *sb, ext4_group_t grp,
 607                              unsigned long ino, ext4_fsblk_t block,
 608                              const char *fmt, ...)
 609 __releases(bitlock)
 610 __acquires(bitlock)
 611 {
 612         struct va_format vaf;
 613         va_list args;
 614         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 615
 616         es->s_last_error_ino = cpu_to_le32(ino);
 617         es->s_last_error_block = cpu_to_le64(block);
 618         __save_error_info(sb, function, line);
 619
 620         va_start(args, fmt);
 621
 622         vaf.fmt = fmt;
 623         vaf.va = &args;
 624         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 625                sb->s_id, function, line, grp);
 626         if (ino)
 627                 printk(KERN_CONT "inode %lu: ", ino);
 628         if (block)
 629                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 630         printk(KERN_CONT "%pV\n", &vaf);
 631         va_end(args);
 632
 633         if (test_opt(sb, ERRORS_CONT)) {
 634                 ext4_commit_super(sb, 0);
 635                 return;
 636         }
 637
 638         ext4_unlock_group(sb, grp);
 639         ext4_handle_error(sb);
 640         /*
 641          * We only get here in the ERRORS_RO case; relocking the group
 642          * may be dangerous, but nothing bad will happen since the
 643          * filesystem will have already been marked read/only and the
 644          * journal has been aborted.  We return 1 as a hint to callers
 645          * who might what to use the return value from
 646          * ext4_grp_locked_error() to distinguish between the
 647          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 648          * aggressively from the ext4 function in question, with a
 649          * more appropriate error code.
 650          */
 651         ext4_lock_group(sb, grp);
 652         return;
 653 }
 654
 655 void ext4_update_dynamic_rev(struct super_block *sb)
 656 {
 657         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 658
 659         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 660                 return;
 661
 662         ext4_warning(sb,
 663                      "updating to rev %d because of new feature flag, "
 664                      "running e2fsck is recommended",
 665                      EXT4_DYNAMIC_REV);
 666
 667         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 668         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 669         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 670         /* leave es->s_feature_*compat flags alone */
 671         /* es->s_uuid will be set by e2fsck if empty */
 672
 673         /*
 674          * The rest of the superblock fields should be zero, and if not it
 675          * means they are likely already in use, so leave them alone.  We
 676          * can leave it up to e2fsck to clean up any inconsistencies there.
 677          */
 678 }
 679
 680 /*
 681  * Open the external journal device
 682  */
 683 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 684 {
 685         struct block_device *bdev;
 686         char b[BDEVNAME_SIZE];
 687
 688         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 689         if (IS_ERR(bdev))
 690                 goto fail;
 691         return bdev;
 692
 693 fail:
 694         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 695                         __bdevname(dev, b), PTR_ERR(bdev));
 696         return NULL;
 697 }
 698
 699 /*
 700  * Release the journal device
 701  */
 702 static int ext4_blkdev_put(struct block_device *bdev)
 703 {
 704         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 705 }
 706
 707 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 708 {
 709         struct block_device *bdev;
 710         int ret = -ENODEV;
 711
 712         bdev = sbi->journal_bdev;
 713         if (bdev) {
 714                 ret = ext4_blkdev_put(bdev);
 715                 sbi->journal_bdev = NULL;
 716         }
 717         return ret;
 718 }
 719
 720 static inline struct inode *orphan_list_entry(struct list_head *l)
 721 {
 722         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 723 }
 724
 725 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 726 {
 727         struct list_head *l;
 728
 729         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 730                  le32_to_cpu(sbi->s_es->s_last_orphan));
 731
 732         printk(KERN_ERR "sb_info orphan list:\n");
 733         list_for_each(l, &sbi->s_orphan) {
 734                 struct inode *inode = orphan_list_entry(l);
 735                 printk(KERN_ERR "  "
 736                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 737                        inode->i_sb->s_id, inode->i_ino, inode,
 738                        inode->i_mode, inode->i_nlink,
 739                        NEXT_ORPHAN(inode));
 740         }
 741 }
 742
 743 static void ext4_put_super(struct super_block *sb)
 744 {
 745         struct ext4_sb_info *sbi = EXT4_SB(sb);
 746         struct ext4_super_block *es = sbi->s_es;
 747         int i, err;
 748
 749         ext4_unregister_li_request(sb);
 750         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 751
 752         flush_workqueue(sbi->dio_unwritten_wq);
 753         destroy_workqueue(sbi->dio_unwritten_wq);
 754
 755         if (sbi->s_journal) {
 756                 err = jbd2_journal_destroy(sbi->s_journal);
 757                 sbi->s_journal = NULL;
 758                 if (err < 0)
 759                         ext4_abort(sb, "Couldn't clean up the journal");
 760         }
 761
 762         ext4_es_unregister_shrinker(sb);
 763         del_timer(&sbi->s_err_report);
 764         ext4_release_system_zone(sb);
 765         ext4_mb_release(sb);
 766         ext4_ext_release(sb);
 767         ext4_xattr_put_super(sb);
 768
 769         if (!(sb->s_flags & MS_RDONLY)) {
 770                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 771                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 772         }
 773         if (!(sb->s_flags & MS_RDONLY))
 774                 ext4_commit_super(sb, 1);
 775
 776         if (sbi->s_proc) {
 777                 remove_proc_entry("options", sbi->s_proc);
 778                 remove_proc_entry(sb->s_id, ext4_proc_root);
 779         }
 780         kobject_del(&sbi->s_kobj);
 781
 782         for (i = 0; i < sbi->s_gdb_count; i++)
 783                 brelse(sbi->s_group_desc[i]);
 784         ext4_kvfree(sbi->s_group_desc);
 785         ext4_kvfree(sbi->s_flex_groups);
 786         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 787         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 788         percpu_counter_destroy(&sbi->s_dirs_counter);
 789         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 790         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 791         brelse(sbi->s_sbh);
 792 #ifdef CONFIG_QUOTA
 793         for (i = 0; i < MAXQUOTAS; i++)
 794                 kfree(sbi->s_qf_names[i]);
 795 #endif
 796
 797         /* Debugging code just in case the in-memory inode orphan list
 798          * isn't empty.  The on-disk one can be non-empty if we've
 799          * detected an error and taken the fs readonly, but the
 800          * in-memory list had better be clean by this point. */
 801         if (!list_empty(&sbi->s_orphan))
 802                 dump_orphan_list(sb, sbi);
 803         J_ASSERT(list_empty(&sbi->s_orphan));
 804
 805         invalidate_bdev(sb->s_bdev);
 806         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 807                 /*
 808                  * Invalidate the journal device's buffers.  We don't want them
 809                  * floating about in memory - the physical journal device may
 810                  * hotswapped, and it breaks the `ro-after' testing code.
 811                  */
 812                 sync_blockdev(sbi->journal_bdev);
 813                 invalidate_bdev(sbi->journal_bdev);
 814                 ext4_blkdev_remove(sbi);
 815         }
 816         if (sbi->s_mmp_tsk)
 817                 kthread_stop(sbi->s_mmp_tsk);
 818         sb->s_fs_info = NULL;
 819         /*
 820          * Now that we are completely done shutting down the
 821          * superblock, we need to actually destroy the kobject.
 822          */
 823         kobject_put(&sbi->s_kobj);
 824         wait_for_completion(&sbi->s_kobj_unregister);
 825         if (sbi->s_chksum_driver)
 826                 crypto_free_shash(sbi->s_chksum_driver);
 827         kfree(sbi->s_blockgroup_lock);
 828         kfree(sbi);
 829 }
 830
 831 static struct kmem_cache *ext4_inode_cachep;
 832
 833 /*
 834  * Called inside transaction, so use GFP_NOFS
 835  */
 836 static struct inode *ext4_alloc_inode(struct super_block *sb)
 837 {
 838         struct ext4_inode_info *ei;
 839
 840         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 841         if (!ei)
 842                 return NULL;
 843
 844         ei->vfs_inode.i_version = 1;
 845         INIT_LIST_HEAD(&ei->i_prealloc_list);
 846         spin_lock_init(&ei->i_prealloc_lock);
 847         ext4_es_init_tree(&ei->i_es_tree);
 848         rwlock_init(&ei->i_es_lock);
 849         INIT_LIST_HEAD(&ei->i_es_lru);
 850         ei->i_es_lru_nr = 0;
 851         ei->i_reserved_data_blocks = 0;
 852         ei->i_reserved_meta_blocks = 0;
 853         ei->i_allocated_meta_blocks = 0;
 854         ei->i_da_metadata_calc_len = 0;
 855         ei->i_da_metadata_calc_last_lblock = 0;
 856         spin_lock_init(&(ei->i_block_reservation_lock));
 857 #ifdef CONFIG_QUOTA
 858         ei->i_reserved_quota = 0;
 859 #endif
 860         ei->jinode = NULL;
 861         INIT_LIST_HEAD(&ei->i_completed_io_list);
 862         spin_lock_init(&ei->i_completed_io_lock);
 863         ei->i_sync_tid = 0;
 864         ei->i_datasync_tid = 0;
 865         atomic_set(&ei->i_ioend_count, 0);
 866         atomic_set(&ei->i_unwritten, 0);
 867         INIT_WORK(&ei->i_unwritten_work, ext4_end_io_work);
 868
 869         return &ei->vfs_inode;
 870 }
 871
 872 static int ext4_drop_inode(struct inode *inode)
 873 {
 874         int drop = generic_drop_inode(inode);
 875
 876         trace_ext4_drop_inode(inode, drop);
 877         return drop;
 878 }
 879
 880 static void ext4_i_callback(struct rcu_head *head)
 881 {
 882         struct inode *inode = container_of(head, struct inode, i_rcu);
 883         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 884 }
 885
 886 static void ext4_destroy_inode(struct inode *inode)
 887 {
 888         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 889                 ext4_msg(inode->i_sb, KERN_ERR,
 890                          "Inode %lu (%p): orphan list check failed!",
 891                          inode->i_ino, EXT4_I(inode));
 892                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 893                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 894                                 true);
 895                 dump_stack();
 896         }
 897         call_rcu(&inode->i_rcu, ext4_i_callback);
 898 }
 899
 900 static void init_once(void *foo)
 901 {
 902         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 903
 904         INIT_LIST_HEAD(&ei->i_orphan);
 905         init_rwsem(&ei->xattr_sem);
 906         init_rwsem(&ei->i_data_sem);
 907         inode_init_once(&ei->vfs_inode);
 908 }
 909
 910 static int init_inodecache(void)
 911 {
 912         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 913                                              sizeof(struct ext4_inode_info),
 914                                              0, (SLAB_RECLAIM_ACCOUNT|
 915                                                 SLAB_MEM_SPREAD),
 916                                              init_once);
 917         if (ext4_inode_cachep == NULL)
 918                 return -ENOMEM;
 919         return 0;
 920 }
 921
 922 static void destroy_inodecache(void)
 923 {
 924         /*
 925          * Make sure all delayed rcu free inodes are flushed before we
 926          * destroy cache.
 927          */
 928         rcu_barrier();
 929         kmem_cache_destroy(ext4_inode_cachep);
 930 }
 931
 932 void ext4_clear_inode(struct inode *inode)
 933 {
 934         invalidate_inode_buffers(inode);
 935         clear_inode(inode);
 936         dquot_drop(inode);
 937         ext4_discard_preallocations(inode);
 938         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 939         ext4_es_lru_del(inode);
 940         if (EXT4_I(inode)->jinode) {
 941                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 942                                                EXT4_I(inode)->jinode);
 943                 jbd2_free_inode(EXT4_I(inode)->jinode);
 944                 EXT4_I(inode)->jinode = NULL;
 945         }
 946 }
 947
 948 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
 949                                         u64 ino, u32 generation)
 950 {
 951         struct inode *inode;
 952
 953         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
 954                 return ERR_PTR(-ESTALE);
 955         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
 956                 return ERR_PTR(-ESTALE);
 957
 958         /* iget isn't really right if the inode is currently unallocated!!
 959          *
 960          * ext4_read_inode will return a bad_inode if the inode had been
 961          * deleted, so we should be safe.
 962          *
 963          * Currently we don't know the generation for parent directory, so
 964          * a generation of 0 means "accept any"
 965          */
 966         inode = ext4_iget(sb, ino);
 967         if (IS_ERR(inode))
 968                 return ERR_CAST(inode);
 969         if (generation && inode->i_generation != generation) {
 970                 iput(inode);
 971                 return ERR_PTR(-ESTALE);
 972         }
 973
 974         return inode;
 975 }
 976
 977 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
 978                                         int fh_len, int fh_type)
 979 {
 980         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 981                                     ext4_nfs_get_inode);
 982 }
 983
 984 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 985                                         int fh_len, int fh_type)
 986 {
 987         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 988                                     ext4_nfs_get_inode);
 989 }
 990
 991 /*
 992  * Try to release metadata pages (indirect blocks, directories) which are
 993  * mapped via the block device.  Since these pages could have journal heads
 994  * which would prevent try_to_free_buffers() from freeing them, we must use
 995  * jbd2 layer's try_to_free_buffers() function to release them.
 996  */
 997 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
 998                                  gfp_t wait)
 999 {
1000         journal_t *journal = EXT4_SB(sb)->s_journal;
1001
1002         WARN_ON(PageChecked(page));
1003         if (!page_has_buffers(page))
1004                 return 0;
1005         if (journal)
1006                 return jbd2_journal_try_to_free_buffers(journal, page,
1007                                                         wait & ~__GFP_WAIT);
1008         return try_to_free_buffers(page);
1009 }
1010
1011 #ifdef CONFIG_QUOTA
1012 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1013 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1014
1015 static int ext4_write_dquot(struct dquot *dquot);
1016 static int ext4_acquire_dquot(struct dquot *dquot);
1017 static int ext4_release_dquot(struct dquot *dquot);
1018 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1019 static int ext4_write_info(struct super_block *sb, int type);
1020 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1021                          struct path *path);
1022 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1023                                  int format_id);
1024 static int ext4_quota_off(struct super_block *sb, int type);
1025 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1026 static int ext4_quota_on_mount(struct super_block *sb, int type);
1027 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1028                                size_t len, loff_t off);
1029 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1030                                 const char *data, size_t len, loff_t off);
1031 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1032                              unsigned int flags);
1033 static int ext4_enable_quotas(struct super_block *sb);
1034
1035 static const struct dquot_operations ext4_quota_operations = {
1036         .get_reserved_space = ext4_get_reserved_space,
1037         .write_dquot    = ext4_write_dquot,
1038         .acquire_dquot  = ext4_acquire_dquot,
1039         .release_dquot  = ext4_release_dquot,
1040         .mark_dirty     = ext4_mark_dquot_dirty,
1041         .write_info     = ext4_write_info,
1042         .alloc_dquot    = dquot_alloc,
1043         .destroy_dquot  = dquot_destroy,
1044 };
1045
1046 static const struct quotactl_ops ext4_qctl_operations = {
1047         .quota_on       = ext4_quota_on,
1048         .quota_off      = ext4_quota_off,
1049         .quota_sync     = dquot_quota_sync,
1050         .get_info       = dquot_get_dqinfo,
1051         .set_info       = dquot_set_dqinfo,
1052         .get_dqblk      = dquot_get_dqblk,
1053         .set_dqblk      = dquot_set_dqblk
1054 };
1055
1056 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1057         .quota_on_meta  = ext4_quota_on_sysfile,
1058         .quota_off      = ext4_quota_off_sysfile,
1059         .quota_sync     = dquot_quota_sync,
1060         .get_info       = dquot_get_dqinfo,
1061         .set_info       = dquot_set_dqinfo,
1062         .get_dqblk      = dquot_get_dqblk,
1063         .set_dqblk      = dquot_set_dqblk
1064 };
1065 #endif
1066
1067 static const struct super_operations ext4_sops = {
1068         .alloc_inode    = ext4_alloc_inode,
1069         .destroy_inode  = ext4_destroy_inode,
1070         .write_inode    = ext4_write_inode,
1071         .dirty_inode    = ext4_dirty_inode,
1072         .drop_inode     = ext4_drop_inode,
1073         .evict_inode    = ext4_evict_inode,
1074         .put_super      = ext4_put_super,
1075         .sync_fs        = ext4_sync_fs,
1076         .freeze_fs      = ext4_freeze,
1077         .unfreeze_fs    = ext4_unfreeze,
1078         .statfs         = ext4_statfs,
1079         .remount_fs     = ext4_remount,
1080         .show_options   = ext4_show_options,
1081 #ifdef CONFIG_QUOTA
1082         .quota_read     = ext4_quota_read,
1083         .quota_write    = ext4_quota_write,
1084 #endif
1085         .bdev_try_to_free_page = bdev_try_to_free_page,
1086 };
1087
1088 static const struct super_operations ext4_nojournal_sops = {
1089         .alloc_inode    = ext4_alloc_inode,
1090         .destroy_inode  = ext4_destroy_inode,
1091         .write_inode    = ext4_write_inode,
1092         .dirty_inode    = ext4_dirty_inode,
1093         .drop_inode     = ext4_drop_inode,
1094         .evict_inode    = ext4_evict_inode,
1095         .put_super      = ext4_put_super,
1096         .statfs         = ext4_statfs,
1097         .remount_fs     = ext4_remount,
1098         .show_options   = ext4_show_options,
1099 #ifdef CONFIG_QUOTA
1100         .quota_read     = ext4_quota_read,
1101         .quota_write    = ext4_quota_write,
1102 #endif
1103         .bdev_try_to_free_page = bdev_try_to_free_page,
1104 };
1105
1106 static const struct export_operations ext4_export_ops = {
1107         .fh_to_dentry = ext4_fh_to_dentry,
1108         .fh_to_parent = ext4_fh_to_parent,
1109         .get_parent = ext4_get_parent,
1110 };
1111
1112 enum {
1113         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1114         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1115         Opt_nouid32, Opt_debug, Opt_removed,
1116         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1117         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1118         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1119         Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1120         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1121         Opt_data_err_abort, Opt_data_err_ignore,
1122         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1123         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1124         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1125         Opt_usrquota, Opt_grpquota, Opt_i_version,
1126         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1127         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1128         Opt_inode_readahead_blks, Opt_journal_ioprio,
1129         Opt_dioread_nolock, Opt_dioread_lock,
1130         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1131         Opt_max_dir_size_kb,
1132 };
1133
1134 static const match_table_t tokens = {
1135         {Opt_bsd_df, "bsddf"},
1136         {Opt_minix_df, "minixdf"},
1137         {Opt_grpid, "grpid"},
1138         {Opt_grpid, "bsdgroups"},
1139         {Opt_nogrpid, "nogrpid"},
1140         {Opt_nogrpid, "sysvgroups"},
1141         {Opt_resgid, "resgid=%u"},
1142         {Opt_resuid, "resuid=%u"},
1143         {Opt_sb, "sb=%u"},
1144         {Opt_err_cont, "errors=continue"},
1145         {Opt_err_panic, "errors=panic"},
1146         {Opt_err_ro, "errors=remount-ro"},
1147         {Opt_nouid32, "nouid32"},
1148         {Opt_debug, "debug"},
1149         {Opt_removed, "oldalloc"},
1150         {Opt_removed, "orlov"},
1151         {Opt_user_xattr, "user_xattr"},
1152         {Opt_nouser_xattr, "nouser_xattr"},
1153         {Opt_acl, "acl"},
1154         {Opt_noacl, "noacl"},
1155         {Opt_noload, "norecovery"},
1156         {Opt_noload, "noload"},
1157         {Opt_removed, "nobh"},
1158         {Opt_removed, "bh"},
1159         {Opt_commit, "commit=%u"},
1160         {Opt_min_batch_time, "min_batch_time=%u"},
1161         {Opt_max_batch_time, "max_batch_time=%u"},
1162         {Opt_journal_dev, "journal_dev=%u"},
1163         {Opt_journal_checksum, "journal_checksum"},
1164         {Opt_journal_async_commit, "journal_async_commit"},
1165         {Opt_abort, "abort"},
1166         {Opt_data_journal, "data=journal"},
1167         {Opt_data_ordered, "data=ordered"},
1168         {Opt_data_writeback, "data=writeback"},
1169         {Opt_data_err_abort, "data_err=abort"},
1170         {Opt_data_err_ignore, "data_err=ignore"},
1171         {Opt_offusrjquota, "usrjquota="},
1172         {Opt_usrjquota, "usrjquota=%s"},
1173         {Opt_offgrpjquota, "grpjquota="},
1174         {Opt_grpjquota, "grpjquota=%s"},
1175         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1176         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1177         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1178         {Opt_grpquota, "grpquota"},
1179         {Opt_noquota, "noquota"},
1180         {Opt_quota, "quota"},
1181         {Opt_usrquota, "usrquota"},
1182         {Opt_barrier, "barrier=%u"},
1183         {Opt_barrier, "barrier"},
1184         {Opt_nobarrier, "nobarrier"},
1185         {Opt_i_version, "i_version"},
1186         {Opt_stripe, "stripe=%u"},
1187         {Opt_delalloc, "delalloc"},
1188         {Opt_nodelalloc, "nodelalloc"},
1189         {Opt_removed, "mblk_io_submit"},
1190         {Opt_removed, "nomblk_io_submit"},
1191         {Opt_block_validity, "block_validity"},
1192         {Opt_noblock_validity, "noblock_validity"},
1193         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1194         {Opt_journal_ioprio, "journal_ioprio=%u"},
1195         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1196         {Opt_auto_da_alloc, "auto_da_alloc"},
1197         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1198         {Opt_dioread_nolock, "dioread_nolock"},
1199         {Opt_dioread_lock, "dioread_lock"},
1200         {Opt_discard, "discard"},
1201         {Opt_nodiscard, "nodiscard"},
1202         {Opt_init_itable, "init_itable=%u"},
1203         {Opt_init_itable, "init_itable"},
1204         {Opt_noinit_itable, "noinit_itable"},
1205         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1206         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1207         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1208         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1209         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1210         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1211         {Opt_err, NULL},
1212 };
1213
1214 static ext4_fsblk_t get_sb_block(void **data)
1215 {
1216         ext4_fsblk_t    sb_block;
1217         char            *options = (char *) *data;
1218
1219         if (!options || strncmp(options, "sb=", 3) != 0)
1220                 return 1;       /* Default location */
1221
1222         options += 3;
1223         /* TODO: use simple_strtoll with >32bit ext4 */
1224         sb_block = simple_strtoul(options, &options, 0);
1225         if (*options && *options != ',') {
1226                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1227                        (char *) *data);
1228                 return 1;
1229         }
1230         if (*options == ',')
1231                 options++;
1232         *data = (void *) options;
1233
1234         return sb_block;
1235 }
1236
1237 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1238 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1239         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1240
1241 #ifdef CONFIG_QUOTA
1242 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1243 {
1244         struct ext4_sb_info *sbi = EXT4_SB(sb);
1245         char *qname;
1246         int ret = -1;
1247
1248         if (sb_any_quota_loaded(sb) &&
1249                 !sbi->s_qf_names[qtype]) {
1250                 ext4_msg(sb, KERN_ERR,
1251                         "Cannot change journaled "
1252                         "quota options when quota turned on");
1253                 return -1;
1254         }
1255         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1256                 ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1257                          "when QUOTA feature is enabled");
1258                 return -1;
1259         }
1260         qname = match_strdup(args);
1261         if (!qname) {
1262                 ext4_msg(sb, KERN_ERR,
1263                         "Not enough memory for storing quotafile name");
1264                 return -1;
1265         }
1266         if (sbi->s_qf_names[qtype]) {
1267                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1268                         ret = 1;
1269                 else
1270                         ext4_msg(sb, KERN_ERR,
1271                                  "%s quota file already specified",
1272                                  QTYPE2NAME(qtype));
1273                 goto errout;
1274         }
1275         if (strchr(qname, '/')) {
1276                 ext4_msg(sb, KERN_ERR,
1277                         "quotafile must be on filesystem root");
1278                 goto errout;
1279         }
1280         sbi->s_qf_names[qtype] = qname;
1281         set_opt(sb, QUOTA);
1282         return 1;
1283 errout:
1284         kfree(qname);
1285         return ret;
1286 }
1287
1288 static int clear_qf_name(struct super_block *sb, int qtype)
1289 {
1290
1291         struct ext4_sb_info *sbi = EXT4_SB(sb);
1292
1293         if (sb_any_quota_loaded(sb) &&
1294                 sbi->s_qf_names[qtype]) {
1295                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1296                         " when quota turned on");
1297                 return -1;
1298         }
1299         kfree(sbi->s_qf_names[qtype]);
1300         sbi->s_qf_names[qtype] = NULL;
1301         return 1;
1302 }
1303 #endif
1304
1305 #define MOPT_SET        0x0001
1306 #define MOPT_CLEAR      0x0002
1307 #define MOPT_NOSUPPORT  0x0004
1308 #define MOPT_EXPLICIT   0x0008
1309 #define MOPT_CLEAR_ERR  0x0010
1310 #define MOPT_GTE0       0x0020
1311 #ifdef CONFIG_QUOTA
1312 #define MOPT_Q          0
1313 #define MOPT_QFMT       0x0040
1314 #else
1315 #define MOPT_Q          MOPT_NOSUPPORT
1316 #define MOPT_QFMT       MOPT_NOSUPPORT
1317 #endif
1318 #define MOPT_DATAJ      0x0080
1319 #define MOPT_NO_EXT2    0x0100
1320 #define MOPT_NO_EXT3    0x0200
1321 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1322
1323 static const struct mount_opts {
1324         int     token;
1325         int     mount_opt;
1326         int     flags;
1327 } ext4_mount_opts[] = {
1328         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1329         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1330         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1331         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1332         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1333         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1334         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1335          MOPT_EXT4_ONLY | MOPT_SET},
1336         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1337          MOPT_EXT4_ONLY | MOPT_CLEAR},
1338         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1339         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1340         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1341          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1342         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1343          MOPT_EXT4_ONLY | MOPT_CLEAR | MOPT_EXPLICIT},
1344         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1345          MOPT_EXT4_ONLY | MOPT_SET},
1346         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1347                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1348          MOPT_EXT4_ONLY | MOPT_SET},
1349         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1350         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1351         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1352         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1353         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1354          MOPT_NO_EXT2 | MOPT_SET},
1355         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1356          MOPT_NO_EXT2 | MOPT_CLEAR},
1357         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1358         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1359         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1360         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1361         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1362         {Opt_commit, 0, MOPT_GTE0},
1363         {Opt_max_batch_time, 0, MOPT_GTE0},
1364         {Opt_min_batch_time, 0, MOPT_GTE0},
1365         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1366         {Opt_init_itable, 0, MOPT_GTE0},
1367         {Opt_stripe, 0, MOPT_GTE0},
1368         {Opt_resuid, 0, MOPT_GTE0},
1369         {Opt_resgid, 0, MOPT_GTE0},
1370         {Opt_journal_dev, 0, MOPT_GTE0},
1371         {Opt_journal_ioprio, 0, MOPT_GTE0},
1372         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1373         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1374         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1375          MOPT_NO_EXT2 | MOPT_DATAJ},
1376         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1377         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1378 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1379         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1380         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1381 #else
1382         {Opt_acl, 0, MOPT_NOSUPPORT},
1383         {Opt_noacl, 0, MOPT_NOSUPPORT},
1384 #endif
1385         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1386         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1387         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1388         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1389                                                         MOPT_SET | MOPT_Q},
1390         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1391                                                         MOPT_SET | MOPT_Q},
1392         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1393                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1394         {Opt_usrjquota, 0, MOPT_Q},
1395         {Opt_grpjquota, 0, MOPT_Q},
1396         {Opt_offusrjquota, 0, MOPT_Q},
1397         {Opt_offgrpjquota, 0, MOPT_Q},
1398         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1399         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1400         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1401         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1402         {Opt_err, 0, 0}
1403 };
1404
1405 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1406                             substring_t *args, unsigned long *journal_devnum,
1407                             unsigned int *journal_ioprio, int is_remount)
1408 {
1409         struct ext4_sb_info *sbi = EXT4_SB(sb);
1410         const struct mount_opts *m;
1411         kuid_t uid;
1412         kgid_t gid;
1413         int arg = 0;
1414
1415 #ifdef CONFIG_QUOTA
1416         if (token == Opt_usrjquota)
1417                 return set_qf_name(sb, USRQUOTA, &args[0]);
1418         else if (token == Opt_grpjquota)
1419                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1420         else if (token == Opt_offusrjquota)
1421                 return clear_qf_name(sb, USRQUOTA);
1422         else if (token == Opt_offgrpjquota)
1423                 return clear_qf_name(sb, GRPQUOTA);
1424 #endif
1425         switch (token) {
1426         case Opt_noacl:
1427         case Opt_nouser_xattr:
1428                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1429                 break;
1430         case Opt_sb:
1431                 return 1;       /* handled by get_sb_block() */
1432         case Opt_removed:
1433                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1434                 return 1;
1435         case Opt_abort:
1436                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1437                 return 1;
1438         case Opt_i_version:
1439                 sb->s_flags |= MS_I_VERSION;
1440                 return 1;
1441         }
1442
1443         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1444                 if (token == m->token)
1445                         break;
1446
1447         if (m->token == Opt_err) {
1448                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1449                          "or missing value", opt);
1450                 return -1;
1451         }
1452
1453         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1454                 ext4_msg(sb, KERN_ERR,
1455                          "Mount option \"%s\" incompatible with ext2", opt);
1456                 return -1;
1457         }
1458         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1459                 ext4_msg(sb, KERN_ERR,
1460                          "Mount option \"%s\" incompatible with ext3", opt);
1461                 return -1;
1462         }
1463
1464         if (args->from && match_int(args, &arg))
1465                 return -1;
1466         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1467                 return -1;
1468         if (m->flags & MOPT_EXPLICIT)
1469                 set_opt2(sb, EXPLICIT_DELALLOC);
1470         if (m->flags & MOPT_CLEAR_ERR)
1471                 clear_opt(sb, ERRORS_MASK);
1472         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1473                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1474                          "options when quota turned on");
1475                 return -1;
1476         }
1477
1478         if (m->flags & MOPT_NOSUPPORT) {
1479                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1480         } else if (token == Opt_commit) {
1481                 if (arg == 0)
1482                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1483                 sbi->s_commit_interval = HZ * arg;
1484         } else if (token == Opt_max_batch_time) {
1485                 if (arg == 0)
1486                         arg = EXT4_DEF_MAX_BATCH_TIME;
1487                 sbi->s_max_batch_time = arg;
1488         } else if (token == Opt_min_batch_time) {
1489                 sbi->s_min_batch_time = arg;
1490         } else if (token == Opt_inode_readahead_blks) {
1491                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1492                         ext4_msg(sb, KERN_ERR,
1493                                  "EXT4-fs: inode_readahead_blks must be "
1494                                  "0 or a power of 2 smaller than 2^31");
1495                         return -1;
1496                 }
1497                 sbi->s_inode_readahead_blks = arg;
1498         } else if (token == Opt_init_itable) {
1499                 set_opt(sb, INIT_INODE_TABLE);
1500                 if (!args->from)
1501                         arg = EXT4_DEF_LI_WAIT_MULT;
1502                 sbi->s_li_wait_mult = arg;
1503         } else if (token == Opt_max_dir_size_kb) {
1504                 sbi->s_max_dir_size_kb = arg;
1505         } else if (token == Opt_stripe) {
1506                 sbi->s_stripe = arg;
1507         } else if (token == Opt_resuid) {
1508                 uid = make_kuid(current_user_ns(), arg);
1509                 if (!uid_valid(uid)) {
1510                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1511                         return -1;
1512                 }
1513                 sbi->s_resuid = uid;
1514         } else if (token == Opt_resgid) {
1515                 gid = make_kgid(current_user_ns(), arg);
1516                 if (!gid_valid(gid)) {
1517                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1518                         return -1;
1519                 }
1520                 sbi->s_resgid = gid;
1521         } else if (token == Opt_journal_dev) {
1522                 if (is_remount) {
1523                         ext4_msg(sb, KERN_ERR,
1524                                  "Cannot specify journal on remount");
1525                         return -1;
1526                 }
1527                 *journal_devnum = arg;
1528         } else if (token == Opt_journal_ioprio) {
1529                 if (arg > 7) {
1530                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1531                                  " (must be 0-7)");
1532                         return -1;
1533                 }
1534                 *journal_ioprio =
1535                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1536         } else if (m->flags & MOPT_DATAJ) {
1537                 if (is_remount) {
1538                         if (!sbi->s_journal)
1539                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1540                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1541                                 ext4_msg(sb, KERN_ERR,
1542                                          "Cannot change data mode on remount");
1543                                 return -1;
1544                         }
1545                 } else {
1546                         clear_opt(sb, DATA_FLAGS);
1547                         sbi->s_mount_opt |= m->mount_opt;
1548                 }
1549 #ifdef CONFIG_QUOTA
1550         } else if (m->flags & MOPT_QFMT) {
1551                 if (sb_any_quota_loaded(sb) &&
1552                     sbi->s_jquota_fmt != m->mount_opt) {
1553                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1554                                  "quota options when quota turned on");
1555                         return -1;
1556                 }
1557                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1558                                                EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1559                         ext4_msg(sb, KERN_ERR,
1560                                  "Cannot set journaled quota options "
1561                                  "when QUOTA feature is enabled");
1562                         return -1;
1563                 }
1564                 sbi->s_jquota_fmt = m->mount_opt;
1565 #endif
1566         } else {
1567                 if (!args->from)
1568                         arg = 1;
1569                 if (m->flags & MOPT_CLEAR)
1570                         arg = !arg;
1571                 else if (unlikely(!(m->flags & MOPT_SET))) {
1572                         ext4_msg(sb, KERN_WARNING,
1573                                  "buggy handling of option %s", opt);
1574                         WARN_ON(1);
1575                         return -1;
1576                 }
1577                 if (arg != 0)
1578                         sbi->s_mount_opt |= m->mount_opt;
1579                 else
1580                         sbi->s_mount_opt &= ~m->mount_opt;
1581         }
1582         return 1;
1583 }
1584
1585 static int parse_options(char *options, struct super_block *sb,
1586                          unsigned long *journal_devnum,
1587                          unsigned int *journal_ioprio,
1588                          int is_remount)
1589 {
1590         struct ext4_sb_info *sbi = EXT4_SB(sb);
1591         char *p;
1592         substring_t args[MAX_OPT_ARGS];
1593         int token;
1594
1595         if (!options)
1596                 return 1;
1597
1598         while ((p = strsep(&options, ",")) != NULL) {
1599                 if (!*p)
1600                         continue;
1601                 /*
1602                  * Initialize args struct so we know whether arg was
1603                  * found; some options take optional arguments.
1604                  */
1605                 args[0].to = args[0].from = NULL;
1606                 token = match_token(p, tokens, args);
1607                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1608                                      journal_ioprio, is_remount) < 0)
1609                         return 0;
1610         }
1611 #ifdef CONFIG_QUOTA
1612         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1613             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1614                 ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1615                          "feature is enabled");
1616                 return 0;
1617         }
1618         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1619                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1620                         clear_opt(sb, USRQUOTA);
1621
1622                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1623                         clear_opt(sb, GRPQUOTA);
1624
1625                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1626                         ext4_msg(sb, KERN_ERR, "old and new quota "
1627                                         "format mixing");
1628                         return 0;
1629                 }
1630
1631                 if (!sbi->s_jquota_fmt) {
1632                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1633                                         "not specified");
1634                         return 0;
1635                 }
1636         } else {
1637                 if (sbi->s_jquota_fmt) {
1638                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1639                                         "specified with no journaling "
1640                                         "enabled");
1641                         return 0;
1642                 }
1643         }
1644 #endif
1645         if (test_opt(sb, DIOREAD_NOLOCK)) {
1646                 int blocksize =
1647                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1648
1649                 if (blocksize < PAGE_CACHE_SIZE) {
1650                         ext4_msg(sb, KERN_ERR, "can't mount with "
1651                                  "dioread_nolock if block size != PAGE_SIZE");
1652                         return 0;
1653                 }
1654         }
1655         return 1;
1656 }
1657
1658 static inline void ext4_show_quota_options(struct seq_file *seq,
1659                                            struct super_block *sb)
1660 {
1661 #if defined(CONFIG_QUOTA)
1662         struct ext4_sb_info *sbi = EXT4_SB(sb);
1663
1664         if (sbi->s_jquota_fmt) {
1665                 char *fmtname = "";
1666
1667                 switch (sbi->s_jquota_fmt) {
1668                 case QFMT_VFS_OLD:
1669                         fmtname = "vfsold";
1670                         break;
1671                 case QFMT_VFS_V0:
1672                         fmtname = "vfsv0";
1673                         break;
1674                 case QFMT_VFS_V1:
1675                         fmtname = "vfsv1";
1676                         break;
1677                 }
1678                 seq_printf(seq, ",jqfmt=%s", fmtname);
1679         }
1680
1681         if (sbi->s_qf_names[USRQUOTA])
1682                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1683
1684         if (sbi->s_qf_names[GRPQUOTA])
1685                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1686
1687         if (test_opt(sb, USRQUOTA))
1688                 seq_puts(seq, ",usrquota");
1689
1690         if (test_opt(sb, GRPQUOTA))
1691                 seq_puts(seq, ",grpquota");
1692 #endif
1693 }
1694
1695 static const char *token2str(int token)
1696 {
1697         const struct match_token *t;
1698
1699         for (t = tokens; t->token != Opt_err; t++)
1700                 if (t->token == token && !strchr(t->pattern, '='))
1701                         break;
1702         return t->pattern;
1703 }
1704
1705 /*
1706  * Show an option if
1707  *  - it's set to a non-default value OR
1708  *  - if the per-sb default is different from the global default
1709  */
1710 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1711                               int nodefs)
1712 {
1713         struct ext4_sb_info *sbi = EXT4_SB(sb);
1714         struct ext4_super_block *es = sbi->s_es;
1715         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1716         const struct mount_opts *m;
1717         char sep = nodefs ? '\n' : ',';
1718
1719 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1720 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1721
1722         if (sbi->s_sb_block != 1)
1723                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1724
1725         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1726                 int want_set = m->flags & MOPT_SET;
1727                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1728                     (m->flags & MOPT_CLEAR_ERR))
1729                         continue;
1730                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1731                         continue; /* skip if same as the default */
1732                 if ((want_set &&
1733                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1734                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1735                         continue; /* select Opt_noFoo vs Opt_Foo */
1736                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1737         }
1738
1739         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1740             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1741                 SEQ_OPTS_PRINT("resuid=%u",
1742                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1743         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1744             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1745                 SEQ_OPTS_PRINT("resgid=%u",
1746                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1747         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1748         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1749                 SEQ_OPTS_PUTS("errors=remount-ro");
1750         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1751                 SEQ_OPTS_PUTS("errors=continue");
1752         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1753                 SEQ_OPTS_PUTS("errors=panic");
1754         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1755                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1756         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1757                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1758         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1759                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1760         if (sb->s_flags & MS_I_VERSION)
1761                 SEQ_OPTS_PUTS("i_version");
1762         if (nodefs || sbi->s_stripe)
1763                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1764         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1765                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1766                         SEQ_OPTS_PUTS("data=journal");
1767                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1768                         SEQ_OPTS_PUTS("data=ordered");
1769                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1770                         SEQ_OPTS_PUTS("data=writeback");
1771         }
1772         if (nodefs ||
1773             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1774                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1775                                sbi->s_inode_readahead_blks);
1776
1777         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1778                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1779                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1780         if (nodefs || sbi->s_max_dir_size_kb)
1781                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1782
1783         ext4_show_quota_options(seq, sb);
1784         return 0;
1785 }
1786
1787 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1788 {
1789         return _ext4_show_options(seq, root->d_sb, 0);
1790 }
1791
1792 static int options_seq_show(struct seq_file *seq, void *offset)
1793 {
1794         struct super_block *sb = seq->private;
1795         int rc;
1796
1797         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1798         rc = _ext4_show_options(seq, sb, 1);
1799         seq_puts(seq, "\n");
1800         return rc;
1801 }
1802
1803 static int options_open_fs(struct inode *inode, struct file *file)
1804 {
1805         return single_open(file, options_seq_show, PDE(inode)->data);
1806 }
1807
1808 static const struct file_operations ext4_seq_options_fops = {
1809         .owner = THIS_MODULE,
1810         .open = options_open_fs,
1811         .read = seq_read,
1812         .llseek = seq_lseek,
1813         .release = single_release,
1814 };
1815
1816 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1817                             int read_only)
1818 {
1819         struct ext4_sb_info *sbi = EXT4_SB(sb);
1820         int res = 0;
1821
1822         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1823                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1824                          "forcing read-only mode");
1825                 res = MS_RDONLY;
1826         }
1827         if (read_only)
1828                 goto done;
1829         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1830                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1831                          "running e2fsck is recommended");
1832         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1833                 ext4_msg(sb, KERN_WARNING,
1834                          "warning: mounting fs with errors, "
1835                          "running e2fsck is recommended");
1836         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1837                  le16_to_cpu(es->s_mnt_count) >=
1838                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1839                 ext4_msg(sb, KERN_WARNING,
1840                          "warning: maximal mount count reached, "
1841                          "running e2fsck is recommended");
1842         else if (le32_to_cpu(es->s_checkinterval) &&
1843                 (le32_to_cpu(es->s_lastcheck) +
1844                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1845                 ext4_msg(sb, KERN_WARNING,
1846                          "warning: checktime reached, "
1847                          "running e2fsck is recommended");
1848         if (!sbi->s_journal)
1849                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1850         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1851                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1852         le16_add_cpu(&es->s_mnt_count, 1);
1853         es->s_mtime = cpu_to_le32(get_seconds());
1854         ext4_update_dynamic_rev(sb);
1855         if (sbi->s_journal)
1856                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1857
1858         ext4_commit_super(sb, 1);
1859 done:
1860         if (test_opt(sb, DEBUG))
1861                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1862                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1863                         sb->s_blocksize,
1864                         sbi->s_groups_count,
1865                         EXT4_BLOCKS_PER_GROUP(sb),
1866                         EXT4_INODES_PER_GROUP(sb),
1867                         sbi->s_mount_opt, sbi->s_mount_opt2);
1868
1869         cleancache_init_fs(sb);
1870         return res;
1871 }
1872
1873 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1874 {
1875         struct ext4_sb_info *sbi = EXT4_SB(sb);
1876         struct flex_groups *new_groups;
1877         int size;
1878
1879         if (!sbi->s_log_groups_per_flex)
1880                 return 0;
1881
1882         size = ext4_flex_group(sbi, ngroup - 1) + 1;
1883         if (size <= sbi->s_flex_groups_allocated)
1884                 return 0;
1885
1886         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1887         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1888         if (!new_groups) {
1889                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1890                          size / (int) sizeof(struct flex_groups));
1891                 return -ENOMEM;
1892         }
1893
1894         if (sbi->s_flex_groups) {
1895                 memcpy(new_groups, sbi->s_flex_groups,
1896                        (sbi->s_flex_groups_allocated *
1897                         sizeof(struct flex_groups)));
1898                 ext4_kvfree(sbi->s_flex_groups);
1899         }
1900         sbi->s_flex_groups = new_groups;
1901         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1902         return 0;
1903 }
1904
1905 static int ext4_fill_flex_info(struct super_block *sb)
1906 {
1907         struct ext4_sb_info *sbi = EXT4_SB(sb);
1908         struct ext4_group_desc *gdp = NULL;
1909         ext4_group_t flex_group;
1910         unsigned int groups_per_flex = 0;
1911         int i, err;
1912
1913         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1914         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1915                 sbi->s_log_groups_per_flex = 0;
1916                 return 1;
1917         }
1918         groups_per_flex = 1U << sbi->s_log_groups_per_flex;
1919
1920         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1921         if (err)
1922                 goto failed;
1923
1924         for (i = 0; i < sbi->s_groups_count; i++) {
1925                 gdp = ext4_get_group_desc(sb, i, NULL);
1926
1927                 flex_group = ext4_flex_group(sbi, i);
1928                 atomic_add(ext4_free_inodes_count(sb, gdp),
1929                            &sbi->s_flex_groups[flex_group].free_inodes);
1930                 atomic64_add(ext4_free_group_clusters(sb, gdp),
1931                              &sbi->s_flex_groups[flex_group].free_clusters);
1932                 atomic_add(ext4_used_dirs_count(sb, gdp),
1933                            &sbi->s_flex_groups[flex_group].used_dirs);
1934         }
1935
1936         return 1;
1937 failed:
1938         return 0;
1939 }
1940
1941 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1942                                    struct ext4_group_desc *gdp)
1943 {
1944         int offset;
1945         __u16 crc = 0;
1946         __le32 le_group = cpu_to_le32(block_group);
1947
1948         if ((sbi->s_es->s_feature_ro_compat &
1949              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1950                 /* Use new metadata_csum algorithm */
1951                 __u16 old_csum;
1952                 __u32 csum32;
1953
1954                 old_csum = gdp->bg_checksum;
1955                 gdp->bg_checksum = 0;
1956                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1957                                      sizeof(le_group));
1958                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1959                                      sbi->s_desc_size);
1960                 gdp->bg_checksum = old_csum;
1961
1962                 crc = csum32 & 0xFFFF;
1963                 goto out;
1964         }
1965
1966         /* old crc16 code */
1967         offset = offsetof(struct ext4_group_desc, bg_checksum);
1968
1969         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1970         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1971         crc = crc16(crc, (__u8 *)gdp, offset);
1972         offset += sizeof(gdp->bg_checksum); /* skip checksum */
1973         /* for checksum of struct ext4_group_desc do the rest...*/
1974         if ((sbi->s_es->s_feature_incompat &
1975              cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1976             offset < le16_to_cpu(sbi->s_es->s_desc_size))
1977                 crc = crc16(crc, (__u8 *)gdp + offset,
1978                             le16_to_cpu(sbi->s_es->s_desc_size) -
1979                                 offset);
1980
1981 out:
1982         return cpu_to_le16(crc);
1983 }
1984
1985 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
1986                                 struct ext4_group_desc *gdp)
1987 {
1988         if (ext4_has_group_desc_csum(sb) &&
1989             (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
1990                                                       block_group, gdp)))
1991                 return 0;
1992
1993         return 1;
1994 }
1995
1996 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
1997                               struct ext4_group_desc *gdp)
1998 {
1999         if (!ext4_has_group_desc_csum(sb))
2000                 return;
2001         gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2002 }
2003
2004 /* Called at mount-time, super-block is locked */
2005 static int ext4_check_descriptors(struct super_block *sb,
2006                                   ext4_group_t *first_not_zeroed)
2007 {
2008         struct ext4_sb_info *sbi = EXT4_SB(sb);
2009         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2010         ext4_fsblk_t last_block;
2011         ext4_fsblk_t block_bitmap;
2012         ext4_fsblk_t inode_bitmap;
2013         ext4_fsblk_t inode_table;
2014         int flexbg_flag = 0;
2015         ext4_group_t i, grp = sbi->s_groups_count;
2016
2017         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2018                 flexbg_flag = 1;
2019
2020         ext4_debug("Checking group descriptors");
2021
2022         for (i = 0; i < sbi->s_groups_count; i++) {
2023                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2024
2025                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2026                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2027                 else
2028                         last_block = first_block +
2029                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2030
2031                 if ((grp == sbi->s_groups_count) &&
2032                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2033                         grp = i;
2034
2035                 block_bitmap = ext4_block_bitmap(sb, gdp);
2036                 if (block_bitmap < first_block || block_bitmap > last_block) {
2037                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2038                                "Block bitmap for group %u not in group "
2039                                "(block %llu)!", i, block_bitmap);
2040                         return 0;
2041                 }
2042                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2043                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2044                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2045                                "Inode bitmap for group %u not in group "
2046                                "(block %llu)!", i, inode_bitmap);
2047                         return 0;
2048                 }
2049                 inode_table = ext4_inode_table(sb, gdp);
2050                 if (inode_table < first_block ||
2051                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2052                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2053                                "Inode table for group %u not in group "
2054                                "(block %llu)!", i, inode_table);
2055                         return 0;
2056                 }
2057                 ext4_lock_group(sb, i);
2058                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2059                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2060                                  "Checksum for group %u failed (%u!=%u)",
2061                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2062                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2063                         if (!(sb->s_flags & MS_RDONLY)) {
2064                                 ext4_unlock_group(sb, i);
2065                                 return 0;
2066                         }
2067                 }
2068                 ext4_unlock_group(sb, i);
2069                 if (!flexbg_flag)
2070                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2071         }
2072         if (NULL != first_not_zeroed)
2073                 *first_not_zeroed = grp;
2074
2075         ext4_free_blocks_count_set(sbi->s_es,
2076                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2077         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2078         return 1;
2079 }
2080
2081 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2082  * the superblock) which were deleted from all directories, but held open by
2083  * a process at the time of a crash.  We walk the list and try to delete these
2084  * inodes at recovery time (only with a read-write filesystem).
2085  *
2086  * In order to keep the orphan inode chain consistent during traversal (in
2087  * case of crash during recovery), we link each inode into the superblock
2088  * orphan list_head and handle it the same way as an inode deletion during
2089  * normal operation (which journals the operations for us).
2090  *
2091  * We only do an iget() and an iput() on each inode, which is very safe if we
2092  * accidentally point at an in-use or already deleted inode.  The worst that
2093  * can happen in this case is that we get a "bit already cleared" message from
2094  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2095  * e2fsck was run on this filesystem, and it must have already done the orphan
2096  * inode cleanup for us, so we can safely abort without any further action.
2097  */
2098 static void ext4_orphan_cleanup(struct super_block *sb,
2099                                 struct ext4_super_block *es)
2100 {
2101         unsigned int s_flags = sb->s_flags;
2102         int nr_orphans = 0, nr_truncates = 0;
2103 #ifdef CONFIG_QUOTA
2104         int i;
2105 #endif
2106         if (!es->s_last_orphan) {
2107                 jbd_debug(4, "no orphan inodes to clean up\n");
2108                 return;
2109         }
2110
2111         if (bdev_read_only(sb->s_bdev)) {
2112                 ext4_msg(sb, KERN_ERR, "write access "
2113                         "unavailable, skipping orphan cleanup");
2114                 return;
2115         }
2116
2117         /* Check if feature set would not allow a r/w mount */
2118         if (!ext4_feature_set_ok(sb, 0)) {
2119                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2120                          "unknown ROCOMPAT features");
2121                 return;
2122         }
2123
2124         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2125                 /* don't clear list on RO mount w/ errors */
2126                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2127                         jbd_debug(1, "Errors on filesystem, "
2128                                   "clearing orphan list.\n");
2129                         es->s_last_orphan = 0;
2130                 }
2131                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2132                 return;
2133         }
2134
2135         if (s_flags & MS_RDONLY) {
2136                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2137                 sb->s_flags &= ~MS_RDONLY;
2138         }
2139 #ifdef CONFIG_QUOTA
2140         /* Needed for iput() to work correctly and not trash data */
2141         sb->s_flags |= MS_ACTIVE;
2142         /* Turn on quotas so that they are updated correctly */
2143         for (i = 0; i < MAXQUOTAS; i++) {
2144                 if (EXT4_SB(sb)->s_qf_names[i]) {
2145                         int ret = ext4_quota_on_mount(sb, i);
2146                         if (ret < 0)
2147                                 ext4_msg(sb, KERN_ERR,
2148                                         "Cannot turn on journaled "
2149                                         "quota: error %d", ret);
2150                 }
2151         }
2152 #endif
2153
2154         while (es->s_last_orphan) {
2155                 struct inode *inode;
2156
2157                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2158                 if (IS_ERR(inode)) {
2159                         es->s_last_orphan = 0;
2160                         break;
2161                 }
2162
2163                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2164                 dquot_initialize(inode);
2165                 if (inode->i_nlink) {
2166                         ext4_msg(sb, KERN_DEBUG,
2167                                 "%s: truncating inode %lu to %lld bytes",
2168                                 __func__, inode->i_ino, inode->i_size);
2169                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2170                                   inode->i_ino, inode->i_size);
2171                         mutex_lock(&inode->i_mutex);
2172                         ext4_truncate(inode);
2173                         mutex_unlock(&inode->i_mutex);
2174                         nr_truncates++;
2175                 } else {
2176                         ext4_msg(sb, KERN_DEBUG,
2177                                 "%s: deleting unreferenced inode %lu",
2178                                 __func__, inode->i_ino);
2179                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2180                                   inode->i_ino);
2181                         nr_orphans++;
2182                 }
2183                 iput(inode);  /* The delete magic happens here! */
2184         }
2185
2186 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2187
2188         if (nr_orphans)
2189                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2190                        PLURAL(nr_orphans));
2191         if (nr_truncates)
2192                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2193                        PLURAL(nr_truncates));
2194 #ifdef CONFIG_QUOTA
2195         /* Turn quotas off */
2196         for (i = 0; i < MAXQUOTAS; i++) {
2197                 if (sb_dqopt(sb)->files[i])
2198                         dquot_quota_off(sb, i);
2199         }
2200 #endif
2201         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2202 }
2203
2204 /*
2205  * Maximal extent format file size.
2206  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2207  * extent format containers, within a sector_t, and within i_blocks
2208  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2209  * so that won't be a limiting factor.
2210  *
2211  * However there is other limiting factor. We do store extents in the form
2212  * of starting block and length, hence the resulting length of the extent
2213  * covering maximum file size must fit into on-disk format containers as
2214  * well. Given that length is always by 1 unit bigger than max unit (because
2215  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2216  *
2217  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2218  */
2219 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2220 {
2221         loff_t res;
2222         loff_t upper_limit = MAX_LFS_FILESIZE;
2223
2224         /* small i_blocks in vfs inode? */
2225         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2226                 /*
2227                  * CONFIG_LBDAF is not enabled implies the inode
2228                  * i_block represent total blocks in 512 bytes
2229                  * 32 == size of vfs inode i_blocks * 8
2230                  */
2231                 upper_limit = (1LL << 32) - 1;
2232
2233                 /* total blocks in file system block size */
2234                 upper_limit >>= (blkbits - 9);
2235                 upper_limit <<= blkbits;
2236         }
2237
2238         /*
2239          * 32-bit extent-start container, ee_block. We lower the maxbytes
2240          * by one fs block, so ee_len can cover the extent of maximum file
2241          * size
2242          */
2243         res = (1LL << 32) - 1;
2244         res <<= blkbits;
2245
2246         /* Sanity check against vm- & vfs- imposed limits */
2247         if (res > upper_limit)
2248                 res = upper_limit;
2249
2250         return res;
2251 }
2252
2253 /*
2254  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2255  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2256  * We need to be 1 filesystem block less than the 2^48 sector limit.
2257  */
2258 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2259 {
2260         loff_t res = EXT4_NDIR_BLOCKS;
2261         int meta_blocks;
2262         loff_t upper_limit;
2263         /* This is calculated to be the largest file size for a dense, block
2264          * mapped file such that the file's total number of 512-byte sectors,
2265          * including data and all indirect blocks, does not exceed (2^48 - 1).
2266          *
2267          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2268          * number of 512-byte sectors of the file.
2269          */
2270
2271         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2272                 /*
2273                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2274                  * the inode i_block field represents total file blocks in
2275                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2276                  */
2277                 upper_limit = (1LL << 32) - 1;
2278
2279                 /* total blocks in file system block size */
2280                 upper_limit >>= (bits - 9);
2281
2282         } else {
2283                 /*
2284                  * We use 48 bit ext4_inode i_blocks
2285                  * With EXT4_HUGE_FILE_FL set the i_blocks
2286                  * represent total number of blocks in
2287                  * file system block size
2288                  */
2289                 upper_limit = (1LL << 48) - 1;
2290
2291         }
2292
2293         /* indirect blocks */
2294         meta_blocks = 1;
2295         /* double indirect blocks */
2296         meta_blocks += 1 + (1LL << (bits-2));
2297         /* tripple indirect blocks */
2298         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2299
2300         upper_limit -= meta_blocks;
2301         upper_limit <<= bits;
2302
2303         res += 1LL << (bits-2);
2304         res += 1LL << (2*(bits-2));
2305         res += 1LL << (3*(bits-2));
2306         res <<= bits;
2307         if (res > upper_limit)
2308                 res = upper_limit;
2309
2310         if (res > MAX_LFS_FILESIZE)
2311                 res = MAX_LFS_FILESIZE;
2312
2313         return res;
2314 }
2315
2316 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2317                                    ext4_fsblk_t logical_sb_block, int nr)
2318 {
2319         struct ext4_sb_info *sbi = EXT4_SB(sb);
2320         ext4_group_t bg, first_meta_bg;
2321         int has_super = 0;
2322
2323         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2324
2325         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2326             nr < first_meta_bg)
2327                 return logical_sb_block + nr + 1;
2328         bg = sbi->s_desc_per_block * nr;
2329         if (ext4_bg_has_super(sb, bg))
2330                 has_super = 1;
2331
2332         return (has_super + ext4_group_first_block_no(sb, bg));
2333 }
2334
2335 /**
2336  * ext4_get_stripe_size: Get the stripe size.
2337  * @sbi: In memory super block info
2338  *
2339  * If we have specified it via mount option, then
2340  * use the mount option value. If the value specified at mount time is
2341  * greater than the blocks per group use the super block value.
2342  * If the super block value is greater than blocks per group return 0.
2343  * Allocator needs it be less than blocks per group.
2344  *
2345  */
2346 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2347 {
2348         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2349         unsigned long stripe_width =
2350                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2351         int ret;
2352
2353         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2354                 ret = sbi->s_stripe;
2355         else if (stripe_width <= sbi->s_blocks_per_group)
2356                 ret = stripe_width;
2357         else if (stride <= sbi->s_blocks_per_group)
2358                 ret = stride;
2359         else
2360                 ret = 0;
2361
2362         /*
2363          * If the stripe width is 1, this makes no sense and
2364          * we set it to 0 to turn off stripe handling code.
2365          */
2366         if (ret <= 1)
2367                 ret = 0;
2368
2369         return ret;
2370 }
2371
2372 /* sysfs supprt */
2373
2374 struct ext4_attr {
2375         struct attribute attr;
2376         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2377         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2378                          const char *, size_t);
2379         int offset;
2380 };
2381
2382 static int parse_strtoul(const char *buf,
2383                 unsigned long max, unsigned long *value)
2384 {
2385         char *endp;
2386
2387         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2388         endp = skip_spaces(endp);
2389         if (*endp || *value > max)
2390                 return -EINVAL;
2391
2392         return 0;
2393 }
2394
2395 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2396                                               struct ext4_sb_info *sbi,
2397                                               char *buf)
2398 {
2399         return snprintf(buf, PAGE_SIZE, "%llu\n",
2400                 (s64) EXT4_C2B(sbi,
2401                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2402 }
2403
2404 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2405                                          struct ext4_sb_info *sbi, char *buf)
2406 {
2407         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2408
2409         if (!sb->s_bdev->bd_part)
2410                 return snprintf(buf, PAGE_SIZE, "0\n");
2411         return snprintf(buf, PAGE_SIZE, "%lu\n",
2412                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2413                          sbi->s_sectors_written_start) >> 1);
2414 }
2415
2416 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2417                                           struct ext4_sb_info *sbi, char *buf)
2418 {
2419         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2420
2421         if (!sb->s_bdev->bd_part)
2422                 return snprintf(buf, PAGE_SIZE, "0\n");
2423         return snprintf(buf, PAGE_SIZE, "%llu\n",
2424                         (unsigned long long)(sbi->s_kbytes_written +
2425                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2426                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2427 }
2428
2429 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2430                                           struct ext4_sb_info *sbi,
2431                                           const char *buf, size_t count)
2432 {
2433         unsigned long t;
2434
2435         if (parse_strtoul(buf, 0x40000000, &t))
2436                 return -EINVAL;
2437
2438         if (t && !is_power_of_2(t))
2439                 return -EINVAL;
2440
2441         sbi->s_inode_readahead_blks = t;
2442         return count;
2443 }
2444
2445 static ssize_t sbi_ui_show(struct ext4_attr *a,
2446                            struct ext4_sb_info *sbi, char *buf)
2447 {
2448         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2449
2450         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2451 }
2452
2453 static ssize_t sbi_ui_store(struct ext4_attr *a,
2454                             struct ext4_sb_info *sbi,
2455                             const char *buf, size_t count)
2456 {
2457         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2458         unsigned long t;
2459
2460         if (parse_strtoul(buf, 0xffffffff, &t))
2461                 return -EINVAL;
2462         *ui = t;
2463         return count;
2464 }
2465
2466 static ssize_t trigger_test_error(struct ext4_attr *a,
2467                                   struct ext4_sb_info *sbi,
2468                                   const char *buf, size_t count)
2469 {
2470         int len = count;
2471
2472         if (!capable(CAP_SYS_ADMIN))
2473                 return -EPERM;
2474
2475         if (len && buf[len-1] == '\n')
2476                 len--;
2477
2478         if (len)
2479                 ext4_error(sbi->s_sb, "%.*s", len, buf);
2480         return count;
2481 }
2482
2483 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2484 static struct ext4_attr ext4_attr_##_name = {                   \
2485         .attr = {.name = __stringify(_name), .mode = _mode },   \
2486         .show   = _show,                                        \
2487         .store  = _store,                                       \
2488         .offset = offsetof(struct ext4_sb_info, _elname),       \
2489 }
2490 #define EXT4_ATTR(name, mode, show, store) \
2491 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2492
2493 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2494 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2495 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2496 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2497         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2498 #define ATTR_LIST(name) &ext4_attr_##name.attr
2499
2500 EXT4_RO_ATTR(delayed_allocation_blocks);
2501 EXT4_RO_ATTR(session_write_kbytes);
2502 EXT4_RO_ATTR(lifetime_write_kbytes);
2503 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2504                  inode_readahead_blks_store, s_inode_readahead_blks);
2505 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2506 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2507 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2508 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2509 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2510 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2511 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2512 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2513 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2514 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2515
2516 static struct attribute *ext4_attrs[] = {
2517         ATTR_LIST(delayed_allocation_blocks),
2518         ATTR_LIST(session_write_kbytes),
2519         ATTR_LIST(lifetime_write_kbytes),
2520         ATTR_LIST(inode_readahead_blks),
2521         ATTR_LIST(inode_goal),
2522         ATTR_LIST(mb_stats),
2523         ATTR_LIST(mb_max_to_scan),
2524         ATTR_LIST(mb_min_to_scan),
2525         ATTR_LIST(mb_order2_req),
2526         ATTR_LIST(mb_stream_req),
2527         ATTR_LIST(mb_group_prealloc),
2528         ATTR_LIST(max_writeback_mb_bump),
2529         ATTR_LIST(extent_max_zeroout_kb),
2530         ATTR_LIST(trigger_fs_error),
2531         NULL,
2532 };
2533
2534 /* Features this copy of ext4 supports */
2535 EXT4_INFO_ATTR(lazy_itable_init);
2536 EXT4_INFO_ATTR(batched_discard);
2537 EXT4_INFO_ATTR(meta_bg_resize);
2538
2539 static struct attribute *ext4_feat_attrs[] = {
2540         ATTR_LIST(lazy_itable_init),
2541         ATTR_LIST(batched_discard),
2542         ATTR_LIST(meta_bg_resize),
2543         NULL,
2544 };
2545
2546 static ssize_t ext4_attr_show(struct kobject *kobj,
2547                               struct attribute *attr, char *buf)
2548 {
2549         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2550                                                 s_kobj);
2551         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2552
2553         return a->show ? a->show(a, sbi, buf) : 0;
2554 }
2555
2556 static ssize_t ext4_attr_store(struct kobject *kobj,
2557                                struct attribute *attr,
2558                                const char *buf, size_t len)
2559 {
2560         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2561                                                 s_kobj);
2562         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2563
2564         return a->store ? a->store(a, sbi, buf, len) : 0;
2565 }
2566
2567 static void ext4_sb_release(struct kobject *kobj)
2568 {
2569         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2570                                                 s_kobj);
2571         complete(&sbi->s_kobj_unregister);
2572 }
2573
2574 static const struct sysfs_ops ext4_attr_ops = {
2575         .show   = ext4_attr_show,
2576         .store  = ext4_attr_store,
2577 };
2578
2579 static struct kobj_type ext4_ktype = {
2580         .default_attrs  = ext4_attrs,
2581         .sysfs_ops      = &ext4_attr_ops,
2582         .release        = ext4_sb_release,
2583 };
2584
2585 static void ext4_feat_release(struct kobject *kobj)
2586 {
2587         complete(&ext4_feat->f_kobj_unregister);
2588 }
2589
2590 static struct kobj_type ext4_feat_ktype = {
2591         .default_attrs  = ext4_feat_attrs,
2592         .sysfs_ops      = &ext4_attr_ops,
2593         .release        = ext4_feat_release,
2594 };
2595
2596 /*
2597  * Check whether this filesystem can be mounted based on
2598  * the features present and the RDONLY/RDWR mount requested.
2599  * Returns 1 if this filesystem can be mounted as requested,
2600  * 0 if it cannot be.
2601  */
2602 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2603 {
2604         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2605                 ext4_msg(sb, KERN_ERR,
2606                         "Couldn't mount because of "
2607                         "unsupported optional features (%x)",
2608                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2609                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2610                 return 0;
2611         }
2612
2613         if (readonly)
2614                 return 1;
2615
2616         /* Check that feature set is OK for a read-write mount */
2617         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2618                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2619                          "unsupported optional features (%x)",
2620                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2621                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2622                 return 0;
2623         }
2624         /*
2625          * Large file size enabled file system can only be mounted
2626          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2627          */
2628         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2629                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2630                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2631                                  "cannot be mounted RDWR without "
2632                                  "CONFIG_LBDAF");
2633                         return 0;
2634                 }
2635         }
2636         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2637             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2638                 ext4_msg(sb, KERN_ERR,
2639                          "Can't support bigalloc feature without "
2640                          "extents feature\n");
2641                 return 0;
2642         }
2643
2644 #ifndef CONFIG_QUOTA
2645         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2646             !readonly) {
2647                 ext4_msg(sb, KERN_ERR,
2648                          "Filesystem with quota feature cannot be mounted RDWR "
2649                          "without CONFIG_QUOTA");
2650                 return 0;
2651         }
2652 #endif  /* CONFIG_QUOTA */
2653         return 1;
2654 }
2655
2656 /*
2657  * This function is called once a day if we have errors logged
2658  * on the file system
2659  */
2660 static void print_daily_error_info(unsigned long arg)
2661 {
2662         struct super_block *sb = (struct super_block *) arg;
2663         struct ext4_sb_info *sbi;
2664         struct ext4_super_block *es;
2665
2666         sbi = EXT4_SB(sb);
2667         es = sbi->s_es;
2668
2669         if (es->s_error_count)
2670                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2671                          le32_to_cpu(es->s_error_count));
2672         if (es->s_first_error_time) {
2673                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2674                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2675                        (int) sizeof(es->s_first_error_func),
2676                        es->s_first_error_func,
2677                        le32_to_cpu(es->s_first_error_line));
2678                 if (es->s_first_error_ino)
2679                         printk(": inode %u",
2680                                le32_to_cpu(es->s_first_error_ino));
2681                 if (es->s_first_error_block)
2682                         printk(": block %llu", (unsigned long long)
2683                                le64_to_cpu(es->s_first_error_block));
2684                 printk("\n");
2685         }
2686         if (es->s_last_error_time) {
2687                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2688                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2689                        (int) sizeof(es->s_last_error_func),
2690                        es->s_last_error_func,
2691                        le32_to_cpu(es->s_last_error_line));
2692                 if (es->s_last_error_ino)
2693                         printk(": inode %u",
2694                                le32_to_cpu(es->s_last_error_ino));
2695                 if (es->s_last_error_block)
2696                         printk(": block %llu", (unsigned long long)
2697                                le64_to_cpu(es->s_last_error_block));
2698                 printk("\n");
2699         }
2700         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2701 }
2702
2703 /* Find next suitable group and run ext4_init_inode_table */
2704 static int ext4_run_li_request(struct ext4_li_request *elr)
2705 {
2706         struct ext4_group_desc *gdp = NULL;
2707         ext4_group_t group, ngroups;
2708         struct super_block *sb;
2709         unsigned long timeout = 0;
2710         int ret = 0;
2711
2712         sb = elr->lr_super;
2713         ngroups = EXT4_SB(sb)->s_groups_count;
2714
2715         sb_start_write(sb);
2716         for (group = elr->lr_next_group; group < ngroups; group++) {
2717                 gdp = ext4_get_group_desc(sb, group, NULL);
2718                 if (!gdp) {
2719                         ret = 1;
2720                         break;
2721                 }
2722
2723                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2724                         break;
2725         }
2726
2727         if (group >= ngroups)
2728                 ret = 1;
2729
2730         if (!ret) {
2731                 timeout = jiffies;
2732                 ret = ext4_init_inode_table(sb, group,
2733                                             elr->lr_timeout ? 0 : 1);
2734                 if (elr->lr_timeout == 0) {
2735                         timeout = (jiffies - timeout) *
2736                                   elr->lr_sbi->s_li_wait_mult;
2737                         elr->lr_timeout = timeout;
2738                 }
2739                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2740                 elr->lr_next_group = group + 1;
2741         }
2742         sb_end_write(sb);
2743
2744         return ret;
2745 }
2746
2747 /*
2748  * Remove lr_request from the list_request and free the
2749  * request structure. Should be called with li_list_mtx held
2750  */
2751 static void ext4_remove_li_request(struct ext4_li_request *elr)
2752 {
2753         struct ext4_sb_info *sbi;
2754
2755         if (!elr)
2756                 return;
2757
2758         sbi = elr->lr_sbi;
2759
2760         list_del(&elr->lr_request);
2761         sbi->s_li_request = NULL;
2762         kfree(elr);
2763 }
2764
2765 static void ext4_unregister_li_request(struct super_block *sb)
2766 {
2767         mutex_lock(&ext4_li_mtx);
2768         if (!ext4_li_info) {
2769                 mutex_unlock(&ext4_li_mtx);
2770                 return;
2771         }
2772
2773         mutex_lock(&ext4_li_info->li_list_mtx);
2774         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2775         mutex_unlock(&ext4_li_info->li_list_mtx);
2776         mutex_unlock(&ext4_li_mtx);
2777 }
2778
2779 static struct task_struct *ext4_lazyinit_task;
2780
2781 /*
2782  * This is the function where ext4lazyinit thread lives. It walks
2783  * through the request list searching for next scheduled filesystem.
2784  * When such a fs is found, run the lazy initialization request
2785  * (ext4_rn_li_request) and keep track of the time spend in this
2786  * function. Based on that time we compute next schedule time of
2787  * the request. When walking through the list is complete, compute
2788  * next waking time and put itself into sleep.
2789  */
2790 static int ext4_lazyinit_thread(void *arg)
2791 {
2792         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2793         struct list_head *pos, *n;
2794         struct ext4_li_request *elr;
2795         unsigned long next_wakeup, cur;
2796
2797         BUG_ON(NULL == eli);
2798
2799 cont_thread:
2800         while (true) {
2801                 next_wakeup = MAX_JIFFY_OFFSET;
2802
2803                 mutex_lock(&eli->li_list_mtx);
2804                 if (list_empty(&eli->li_request_list)) {
2805                         mutex_unlock(&eli->li_list_mtx);
2806                         goto exit_thread;
2807                 }
2808
2809                 list_for_each_safe(pos, n, &eli->li_request_list) {
2810                         elr = list_entry(pos, struct ext4_li_request,
2811                                          lr_request);
2812
2813                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2814                                 if (ext4_run_li_request(elr) != 0) {
2815                                         /* error, remove the lazy_init job */
2816                                         ext4_remove_li_request(elr);
2817                                         continue;
2818                                 }
2819                         }
2820
2821                         if (time_before(elr->lr_next_sched, next_wakeup))
2822                                 next_wakeup = elr->lr_next_sched;
2823                 }
2824                 mutex_unlock(&eli->li_list_mtx);
2825
2826                 try_to_freeze();
2827
2828                 cur = jiffies;
2829                 if ((time_after_eq(cur, next_wakeup)) ||
2830                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2831                         cond_resched();
2832                         continue;
2833                 }
2834
2835                 schedule_timeout_interruptible(next_wakeup - cur);
2836
2837                 if (kthread_should_stop()) {
2838                         ext4_clear_request_list();
2839                         goto exit_thread;
2840                 }
2841         }
2842
2843 exit_thread:
2844         /*
2845          * It looks like the request list is empty, but we need
2846          * to check it under the li_list_mtx lock, to prevent any
2847          * additions into it, and of course we should lock ext4_li_mtx
2848          * to atomically free the list and ext4_li_info, because at
2849          * this point another ext4 filesystem could be registering
2850          * new one.
2851          */
2852         mutex_lock(&ext4_li_mtx);
2853         mutex_lock(&eli->li_list_mtx);
2854         if (!list_empty(&eli->li_request_list)) {
2855                 mutex_unlock(&eli->li_list_mtx);
2856                 mutex_unlock(&ext4_li_mtx);
2857                 goto cont_thread;
2858         }
2859         mutex_unlock(&eli->li_list_mtx);
2860         kfree(ext4_li_info);
2861         ext4_li_info = NULL;
2862         mutex_unlock(&ext4_li_mtx);
2863
2864         return 0;
2865 }
2866
2867 static void ext4_clear_request_list(void)
2868 {
2869         struct list_head *pos, *n;
2870         struct ext4_li_request *elr;
2871
2872         mutex_lock(&ext4_li_info->li_list_mtx);
2873         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2874                 elr = list_entry(pos, struct ext4_li_request,
2875                                  lr_request);
2876                 ext4_remove_li_request(elr);
2877         }
2878         mutex_unlock(&ext4_li_info->li_list_mtx);
2879 }
2880
2881 static int ext4_run_lazyinit_thread(void)
2882 {
2883         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2884                                          ext4_li_info, "ext4lazyinit");
2885         if (IS_ERR(ext4_lazyinit_task)) {
2886                 int err = PTR_ERR(ext4_lazyinit_task);
2887                 ext4_clear_request_list();
2888                 kfree(ext4_li_info);
2889                 ext4_li_info = NULL;
2890                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2891                                  "initialization thread\n",
2892                                  err);
2893                 return err;
2894         }
2895         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2896         return 0;
2897 }
2898
2899 /*
2900  * Check whether it make sense to run itable init. thread or not.
2901  * If there is at least one uninitialized inode table, return
2902  * corresponding group number, else the loop goes through all
2903  * groups and return total number of groups.
2904  */
2905 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2906 {
2907         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2908         struct ext4_group_desc *gdp = NULL;
2909
2910         for (group = 0; group < ngroups; group++) {
2911                 gdp = ext4_get_group_desc(sb, group, NULL);
2912                 if (!gdp)
2913                         continue;
2914
2915                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2916                         break;
2917         }
2918
2919         return group;
2920 }
2921
2922 static int ext4_li_info_new(void)
2923 {
2924         struct ext4_lazy_init *eli = NULL;
2925
2926         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2927         if (!eli)
2928                 return -ENOMEM;
2929
2930         INIT_LIST_HEAD(&eli->li_request_list);
2931         mutex_init(&eli->li_list_mtx);
2932
2933         eli->li_state |= EXT4_LAZYINIT_QUIT;
2934
2935         ext4_li_info = eli;
2936
2937         return 0;
2938 }
2939
2940 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2941                                             ext4_group_t start)
2942 {
2943         struct ext4_sb_info *sbi = EXT4_SB(sb);
2944         struct ext4_li_request *elr;
2945         unsigned long rnd;
2946
2947         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2948         if (!elr)
2949                 return NULL;
2950
2951         elr->lr_super = sb;
2952         elr->lr_sbi = sbi;
2953         elr->lr_next_group = start;
2954
2955         /*
2956          * Randomize first schedule time of the request to
2957          * spread the inode table initialization requests
2958          * better.
2959          */
2960         get_random_bytes(&rnd, sizeof(rnd));
2961         elr->lr_next_sched = jiffies + (unsigned long)rnd %
2962                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2963
2964         return elr;
2965 }
2966
2967 int ext4_register_li_request(struct super_block *sb,
2968                              ext4_group_t first_not_zeroed)
2969 {
2970         struct ext4_sb_info *sbi = EXT4_SB(sb);
2971         struct ext4_li_request *elr = NULL;
2972         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2973         int ret = 0;
2974
2975         mutex_lock(&ext4_li_mtx);
2976         if (sbi->s_li_request != NULL) {
2977                 /*
2978                  * Reset timeout so it can be computed again, because
2979                  * s_li_wait_mult might have changed.
2980                  */
2981                 sbi->s_li_request->lr_timeout = 0;
2982                 goto out;
2983         }
2984
2985         if (first_not_zeroed == ngroups ||
2986             (sb->s_flags & MS_RDONLY) ||
2987             !test_opt(sb, INIT_INODE_TABLE))
2988                 goto out;
2989
2990         elr = ext4_li_request_new(sb, first_not_zeroed);
2991         if (!elr) {
2992                 ret = -ENOMEM;
2993                 goto out;
2994         }
2995
2996         if (NULL == ext4_li_info) {
2997                 ret = ext4_li_info_new();
2998                 if (ret)
2999                         goto out;
3000         }
3001
3002         mutex_lock(&ext4_li_info->li_list_mtx);
3003         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3004         mutex_unlock(&ext4_li_info->li_list_mtx);
3005
3006         sbi->s_li_request = elr;
3007         /*
3008          * set elr to NULL here since it has been inserted to
3009          * the request_list and the removal and free of it is
3010          * handled by ext4_clear_request_list from now on.
3011          */
3012         elr = NULL;
3013
3014         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3015                 ret = ext4_run_lazyinit_thread();
3016                 if (ret)
3017                         goto out;
3018         }
3019 out:
3020         mutex_unlock(&ext4_li_mtx);
3021         if (ret)
3022                 kfree(elr);
3023         return ret;
3024 }
3025
3026 /*
3027  * We do not need to lock anything since this is called on
3028  * module unload.
3029  */
3030 static void ext4_destroy_lazyinit_thread(void)
3031 {
3032         /*
3033          * If thread exited earlier
3034          * there's nothing to be done.
3035          */
3036         if (!ext4_li_info || !ext4_lazyinit_task)
3037                 return;
3038
3039         kthread_stop(ext4_lazyinit_task);
3040 }
3041
3042 static int set_journal_csum_feature_set(struct super_block *sb)
3043 {
3044         int ret = 1;
3045         int compat, incompat;
3046         struct ext4_sb_info *sbi = EXT4_SB(sb);
3047
3048         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3049                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3050                 /* journal checksum v2 */
3051                 compat = 0;
3052                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3053         } else {
3054                 /* journal checksum v1 */
3055                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3056                 incompat = 0;
3057         }
3058
3059         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3060                 ret = jbd2_journal_set_features(sbi->s_journal,
3061                                 compat, 0,
3062                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3063                                 incompat);
3064         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3065                 ret = jbd2_journal_set_features(sbi->s_journal,
3066                                 compat, 0,
3067                                 incompat);
3068                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3069                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3070         } else {
3071                 jbd2_journal_clear_features(sbi->s_journal,
3072                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3073                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3074                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
3075         }
3076
3077         return ret;
3078 }
3079
3080 /*
3081  * Note: calculating the overhead so we can be compatible with
3082  * historical BSD practice is quite difficult in the face of
3083  * clusters/bigalloc.  This is because multiple metadata blocks from
3084  * different block group can end up in the same allocation cluster.
3085  * Calculating the exact overhead in the face of clustered allocation
3086  * requires either O(all block bitmaps) in memory or O(number of block
3087  * groups**2) in time.  We will still calculate the superblock for
3088  * older file systems --- and if we come across with a bigalloc file
3089  * system with zero in s_overhead_clusters the estimate will be close to
3090  * correct especially for very large cluster sizes --- but for newer
3091  * file systems, it's better to calculate this figure once at mkfs
3092  * time, and store it in the superblock.  If the superblock value is
3093  * present (even for non-bigalloc file systems), we will use it.
3094  */
3095 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3096                           char *buf)
3097 {
3098         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3099         struct ext4_group_desc  *gdp;
3100         ext4_fsblk_t            first_block, last_block, b;
3101         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3102         int                     s, j, count = 0;
3103
3104         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3105                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3106                         sbi->s_itb_per_group + 2);
3107
3108         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3109                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3110         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3111         for (i = 0; i < ngroups; i++) {
3112                 gdp = ext4_get_group_desc(sb, i, NULL);
3113                 b = ext4_block_bitmap(sb, gdp);
3114                 if (b >= first_block && b <= last_block) {
3115                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3116                         count++;
3117                 }
3118                 b = ext4_inode_bitmap(sb, gdp);
3119                 if (b >= first_block && b <= last_block) {
3120                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3121                         count++;
3122                 }
3123                 b = ext4_inode_table(sb, gdp);
3124                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3125                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3126                                 int c = EXT4_B2C(sbi, b - first_block);
3127                                 ext4_set_bit(c, buf);
3128                                 count++;
3129                         }
3130                 if (i != grp)
3131                         continue;
3132                 s = 0;
3133                 if (ext4_bg_has_super(sb, grp)) {
3134                         ext4_set_bit(s++, buf);
3135                         count++;
3136                 }
3137                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3138                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3139                         count++;
3140                 }
3141         }
3142         if (!count)
3143                 return 0;
3144         return EXT4_CLUSTERS_PER_GROUP(sb) -
3145                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3146 }
3147
3148 /*
3149  * Compute the overhead and stash it in sbi->s_overhead
3150  */
3151 int ext4_calculate_overhead(struct super_block *sb)
3152 {
3153         struct ext4_sb_info *sbi = EXT4_SB(sb);
3154         struct ext4_super_block *es = sbi->s_es;
3155         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3156         ext4_fsblk_t overhead = 0;
3157         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3158
3159         if (!buf)
3160                 return -ENOMEM;
3161
3162         /*
3163          * Compute the overhead (FS structures).  This is constant
3164          * for a given filesystem unless the number of block groups
3165          * changes so we cache the previous value until it does.
3166          */
3167
3168         /*
3169          * All of the blocks before first_data_block are overhead
3170          */
3171         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3172
3173         /*
3174          * Add the overhead found in each block group
3175          */
3176         for (i = 0; i < ngroups; i++) {
3177                 int blks;
3178
3179                 blks = count_overhead(sb, i, buf);
3180                 overhead += blks;
3181                 if (blks)
3182                         memset(buf, 0, PAGE_SIZE);
3183                 cond_resched();
3184         }
3185         /* Add the journal blocks as well */
3186         if (sbi->s_journal)
3187                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3188
3189         sbi->s_overhead = overhead;
3190         smp_wmb();
3191         free_page((unsigned long) buf);
3192         return 0;
3193 }
3194
3195 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3196 {
3197         char *orig_data = kstrdup(data, GFP_KERNEL);
3198         struct buffer_head *bh;
3199         struct ext4_super_block *es = NULL;
3200         struct ext4_sb_info *sbi;
3201         ext4_fsblk_t block;
3202         ext4_fsblk_t sb_block = get_sb_block(&data);
3203         ext4_fsblk_t logical_sb_block;
3204         unsigned long offset = 0;
3205         unsigned long journal_devnum = 0;
3206         unsigned long def_mount_opts;
3207         struct inode *root;
3208         char *cp;
3209         const char *descr;
3210         int ret = -ENOMEM;
3211         int blocksize, clustersize;
3212         unsigned int db_count;
3213         unsigned int i;
3214         int needs_recovery, has_huge_files, has_bigalloc;
3215         __u64 blocks_count;
3216         int err = 0;
3217         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3218         ext4_group_t first_not_zeroed;
3219
3220         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3221         if (!sbi)
3222                 goto out_free_orig;
3223
3224         sbi->s_blockgroup_lock =
3225                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3226         if (!sbi->s_blockgroup_lock) {
3227                 kfree(sbi);
3228                 goto out_free_orig;
3229         }
3230         sb->s_fs_info = sbi;
3231         sbi->s_sb = sb;
3232         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3233         sbi->s_sb_block = sb_block;
3234         if (sb->s_bdev->bd_part)
3235                 sbi->s_sectors_written_start =
3236                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3237
3238         /* Cleanup superblock name */
3239         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3240                 *cp = '!';
3241
3242         /* -EINVAL is default */
3243         ret = -EINVAL;
3244         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3245         if (!blocksize) {
3246                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3247                 goto out_fail;
3248         }
3249
3250         /*
3251          * The ext4 superblock will not be buffer aligned for other than 1kB
3252          * block sizes.  We need to calculate the offset from buffer start.
3253          */
3254         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3255                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3256                 offset = do_div(logical_sb_block, blocksize);
3257         } else {
3258                 logical_sb_block = sb_block;
3259         }
3260
3261         if (!(bh = sb_bread(sb, logical_sb_block))) {
3262                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3263                 goto out_fail;
3264         }
3265         /*
3266          * Note: s_es must be initialized as soon as possible because
3267          *       some ext4 macro-instructions depend on its value
3268          */
3269         es = (struct ext4_super_block *) (bh->b_data + offset);
3270         sbi->s_es = es;
3271         sb->s_magic = le16_to_cpu(es->s_magic);
3272         if (sb->s_magic != EXT4_SUPER_MAGIC)
3273                 goto cantfind_ext4;
3274         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3275
3276         /* Warn if metadata_csum and gdt_csum are both set. */
3277         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3278                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3279             EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3280                 ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3281                              "redundant flags; please run fsck.");
3282
3283         /* Check for a known checksum algorithm */
3284         if (!ext4_verify_csum_type(sb, es)) {
3285                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3286                          "unknown checksum algorithm.");
3287                 silent = 1;
3288                 goto cantfind_ext4;
3289         }
3290
3291         /* Load the checksum driver */
3292         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3293                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3294                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3295                 if (IS_ERR(sbi->s_chksum_driver)) {
3296                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3297                         ret = PTR_ERR(sbi->s_chksum_driver);
3298                         sbi->s_chksum_driver = NULL;
3299                         goto failed_mount;
3300                 }
3301         }
3302
3303         /* Check superblock checksum */
3304         if (!ext4_superblock_csum_verify(sb, es)) {
3305                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3306                          "invalid superblock checksum.  Run e2fsck?");
3307                 silent = 1;
3308                 goto cantfind_ext4;
3309         }
3310
3311         /* Precompute checksum seed for all metadata */
3312         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3313                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3314                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3315                                                sizeof(es->s_uuid));
3316
3317         /* Set defaults before we parse the mount options */
3318         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3319         set_opt(sb, INIT_INODE_TABLE);
3320         if (def_mount_opts & EXT4_DEFM_DEBUG)
3321                 set_opt(sb, DEBUG);
3322         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3323                 set_opt(sb, GRPID);
3324         if (def_mount_opts & EXT4_DEFM_UID16)
3325                 set_opt(sb, NO_UID32);
3326         /* xattr user namespace & acls are now defaulted on */
3327         set_opt(sb, XATTR_USER);
3328 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3329         set_opt(sb, POSIX_ACL);
3330 #endif
3331         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3332                 set_opt(sb, JOURNAL_DATA);
3333         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3334                 set_opt(sb, ORDERED_DATA);
3335         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3336                 set_opt(sb, WRITEBACK_DATA);
3337
3338         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3339                 set_opt(sb, ERRORS_PANIC);
3340         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3341                 set_opt(sb, ERRORS_CONT);
3342         else
3343                 set_opt(sb, ERRORS_RO);
3344         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3345                 set_opt(sb, BLOCK_VALIDITY);
3346         if (def_mount_opts & EXT4_DEFM_DISCARD)
3347                 set_opt(sb, DISCARD);
3348
3349         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3350         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3351         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3352         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3353         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3354
3355         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3356                 set_opt(sb, BARRIER);
3357
3358         /*
3359          * enable delayed allocation by default
3360          * Use -o nodelalloc to turn it off
3361          */
3362         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3363             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3364                 set_opt(sb, DELALLOC);
3365
3366         /*
3367          * set default s_li_wait_mult for lazyinit, for the case there is
3368          * no mount option specified.
3369          */
3370         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3371
3372         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3373                            &journal_devnum, &journal_ioprio, 0)) {
3374                 ext4_msg(sb, KERN_WARNING,
3375                          "failed to parse options in superblock: %s",
3376                          sbi->s_es->s_mount_opts);
3377         }
3378         sbi->s_def_mount_opt = sbi->s_mount_opt;
3379         if (!parse_options((char *) data, sb, &journal_devnum,
3380                            &journal_ioprio, 0))
3381                 goto failed_mount;
3382
3383         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3384                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3385                             "with data=journal disables delayed "
3386                             "allocation and O_DIRECT support!\n");
3387                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3388                         ext4_msg(sb, KERN_ERR, "can't mount with "
3389                                  "both data=journal and delalloc");
3390                         goto failed_mount;
3391                 }
3392                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3393                         ext4_msg(sb, KERN_ERR, "can't mount with "
3394                                  "both data=journal and delalloc");
3395                         goto failed_mount;
3396                 }
3397                 if (test_opt(sb, DELALLOC))
3398                         clear_opt(sb, DELALLOC);
3399         }
3400
3401         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3402                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3403
3404         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3405             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3406              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3407              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3408                 ext4_msg(sb, KERN_WARNING,
3409                        "feature flags set on rev 0 fs, "
3410                        "running e2fsck is recommended");
3411
3412         if (IS_EXT2_SB(sb)) {
3413                 if (ext2_feature_set_ok(sb))
3414                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3415                                  "using the ext4 subsystem");
3416                 else {
3417                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3418                                  "to feature incompatibilities");
3419                         goto failed_mount;
3420                 }
3421         }
3422
3423         if (IS_EXT3_SB(sb)) {
3424                 if (ext3_feature_set_ok(sb))
3425                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3426                                  "using the ext4 subsystem");
3427                 else {
3428                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3429                                  "to feature incompatibilities");
3430                         goto failed_mount;
3431                 }
3432         }
3433
3434         /*
3435          * Check feature flags regardless of the revision level, since we
3436          * previously didn't change the revision level when setting the flags,
3437          * so there is a chance incompat flags are set on a rev 0 filesystem.
3438          */
3439         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3440                 goto failed_mount;
3441
3442         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3443         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3444             blocksize > EXT4_MAX_BLOCK_SIZE) {
3445                 ext4_msg(sb, KERN_ERR,
3446                        "Unsupported filesystem blocksize %d", blocksize);
3447                 goto failed_mount;
3448         }
3449
3450         if (sb->s_blocksize != blocksize) {
3451                 /* Validate the filesystem blocksize */
3452                 if (!sb_set_blocksize(sb, blocksize)) {
3453                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3454                                         blocksize);
3455                         goto failed_mount;
3456                 }
3457
3458                 brelse(bh);
3459                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3460                 offset = do_div(logical_sb_block, blocksize);
3461                 bh = sb_bread(sb, logical_sb_block);
3462                 if (!bh) {
3463                         ext4_msg(sb, KERN_ERR,
3464                                "Can't read superblock on 2nd try");
3465                         goto failed_mount;
3466                 }
3467                 es = (struct ext4_super_block *)(bh->b_data + offset);
3468                 sbi->s_es = es;
3469                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3470                         ext4_msg(sb, KERN_ERR,
3471                                "Magic mismatch, very weird!");
3472                         goto failed_mount;
3473                 }
3474         }
3475
3476         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3477                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3478         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3479                                                       has_huge_files);
3480         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3481
3482         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3483                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3484                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3485         } else {
3486                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3487                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3488                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3489                     (!is_power_of_2(sbi->s_inode_size)) ||
3490                     (sbi->s_inode_size > blocksize)) {
3491                         ext4_msg(sb, KERN_ERR,
3492                                "unsupported inode size: %d",
3493                                sbi->s_inode_size);
3494                         goto failed_mount;
3495                 }
3496                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3497                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3498         }
3499
3500         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3501         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3502                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3503                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3504                     !is_power_of_2(sbi->s_desc_size)) {
3505                         ext4_msg(sb, KERN_ERR,
3506                                "unsupported descriptor size %lu",
3507                                sbi->s_desc_size);
3508                         goto failed_mount;
3509                 }
3510         } else
3511                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3512
3513         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3514         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3515         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3516                 goto cantfind_ext4;
3517
3518         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3519         if (sbi->s_inodes_per_block == 0)
3520                 goto cantfind_ext4;
3521         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3522                                         sbi->s_inodes_per_block;
3523         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3524         sbi->s_sbh = bh;
3525         sbi->s_mount_state = le16_to_cpu(es->s_state);
3526         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3527         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3528
3529         for (i = 0; i < 4; i++)
3530                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3531         sbi->s_def_hash_version = es->s_def_hash_version;
3532         i = le32_to_cpu(es->s_flags);
3533         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3534                 sbi->s_hash_unsigned = 3;
3535         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3536 #ifdef __CHAR_UNSIGNED__
3537                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3538                 sbi->s_hash_unsigned = 3;
3539 #else
3540                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3541 #endif
3542         }
3543
3544         /* Handle clustersize */
3545         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3546         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3547                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3548         if (has_bigalloc) {
3549                 if (clustersize < blocksize) {
3550                         ext4_msg(sb, KERN_ERR,
3551                                  "cluster size (%d) smaller than "
3552                                  "block size (%d)", clustersize, blocksize);
3553                         goto failed_mount;
3554                 }
3555                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3556                         le32_to_cpu(es->s_log_block_size);
3557                 sbi->s_clusters_per_group =
3558                         le32_to_cpu(es->s_clusters_per_group);
3559                 if (sbi->s_clusters_per_group > blocksize * 8) {
3560                         ext4_msg(sb, KERN_ERR,
3561                                  "#clusters per group too big: %lu",
3562                                  sbi->s_clusters_per_group);
3563                         goto failed_mount;
3564                 }
3565                 if (sbi->s_blocks_per_group !=
3566                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3567                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3568                                  "clusters per group (%lu) inconsistent",
3569                                  sbi->s_blocks_per_group,
3570                                  sbi->s_clusters_per_group);
3571                         goto failed_mount;
3572                 }
3573         } else {
3574                 if (clustersize != blocksize) {
3575                         ext4_warning(sb, "fragment/cluster size (%d) != "
3576                                      "block size (%d)", clustersize,
3577                                      blocksize);
3578                         clustersize = blocksize;
3579                 }
3580                 if (sbi->s_blocks_per_group > blocksize * 8) {
3581                         ext4_msg(sb, KERN_ERR,
3582                                  "#blocks per group too big: %lu",
3583                                  sbi->s_blocks_per_group);
3584                         goto failed_mount;
3585                 }
3586                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3587                 sbi->s_cluster_bits = 0;
3588         }
3589         sbi->s_cluster_ratio = clustersize / blocksize;
3590
3591         if (sbi->s_inodes_per_group > blocksize * 8) {
3592                 ext4_msg(sb, KERN_ERR,
3593                        "#inodes per group too big: %lu",
3594                        sbi->s_inodes_per_group);
3595                 goto failed_mount;
3596         }
3597
3598         /*
3599          * Test whether we have more sectors than will fit in sector_t,
3600          * and whether the max offset is addressable by the page cache.
3601          */
3602         err = generic_check_addressable(sb->s_blocksize_bits,
3603                                         ext4_blocks_count(es));
3604         if (err) {
3605                 ext4_msg(sb, KERN_ERR, "filesystem"
3606                          " too large to mount safely on this system");
3607                 if (sizeof(sector_t) < 8)
3608                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3609                 goto failed_mount;
3610         }
3611
3612         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3613                 goto cantfind_ext4;
3614
3615         /* check blocks count against device size */
3616         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3617         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3618                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3619                        "exceeds size of device (%llu blocks)",
3620                        ext4_blocks_count(es), blocks_count);
3621                 goto failed_mount;
3622         }
3623
3624         /*
3625          * It makes no sense for the first data block to be beyond the end
3626          * of the filesystem.
3627          */
3628         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3629                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3630                          "block %u is beyond end of filesystem (%llu)",
3631                          le32_to_cpu(es->s_first_data_block),
3632                          ext4_blocks_count(es));
3633                 goto failed_mount;
3634         }
3635         blocks_count = (ext4_blocks_count(es) -
3636                         le32_to_cpu(es->s_first_data_block) +
3637                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3638         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3639         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3640                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3641                        "(block count %llu, first data block %u, "
3642                        "blocks per group %lu)", sbi->s_groups_count,
3643                        ext4_blocks_count(es),
3644                        le32_to_cpu(es->s_first_data_block),
3645                        EXT4_BLOCKS_PER_GROUP(sb));
3646                 goto failed_mount;
3647         }
3648         sbi->s_groups_count = blocks_count;
3649         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3650                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3651         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3652                    EXT4_DESC_PER_BLOCK(sb);
3653         sbi->s_group_desc = ext4_kvmalloc(db_count *
3654                                           sizeof(struct buffer_head *),
3655                                           GFP_KERNEL);
3656         if (sbi->s_group_desc == NULL) {
3657                 ext4_msg(sb, KERN_ERR, "not enough memory");
3658                 ret = -ENOMEM;
3659                 goto failed_mount;
3660         }
3661
3662         if (ext4_proc_root)
3663                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3664
3665         if (sbi->s_proc)
3666                 proc_create_data("options", S_IRUGO, sbi->s_proc,
3667                                  &ext4_seq_options_fops, sb);
3668
3669         bgl_lock_init(sbi->s_blockgroup_lock);
3670
3671         for (i = 0; i < db_count; i++) {
3672                 block = descriptor_loc(sb, logical_sb_block, i);
3673                 sbi->s_group_desc[i] = sb_bread(sb, block);
3674                 if (!sbi->s_group_desc[i]) {
3675                         ext4_msg(sb, KERN_ERR,
3676                                "can't read group descriptor %d", i);
3677                         db_count = i;
3678                         goto failed_mount2;
3679                 }
3680         }
3681         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3682                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3683                 goto failed_mount2;
3684         }
3685         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3686                 if (!ext4_fill_flex_info(sb)) {
3687                         ext4_msg(sb, KERN_ERR,
3688                                "unable to initialize "
3689                                "flex_bg meta info!");
3690                         goto failed_mount2;
3691                 }
3692
3693         sbi->s_gdb_count = db_count;
3694         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3695         spin_lock_init(&sbi->s_next_gen_lock);
3696
3697         init_timer(&sbi->s_err_report);
3698         sbi->s_err_report.function = print_daily_error_info;
3699         sbi->s_err_report.data = (unsigned long) sb;
3700
3701         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3702                         ext4_count_free_clusters(sb));
3703         if (!err) {
3704                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3705                                 ext4_count_free_inodes(sb));
3706         }
3707         if (!err) {
3708                 err = percpu_counter_init(&sbi->s_dirs_counter,
3709                                 ext4_count_dirs(sb));
3710         }
3711         if (!err) {
3712                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3713         }
3714         if (!err) {
3715                 err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3716         }
3717         if (err) {
3718                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3719                 goto failed_mount3;
3720         }
3721
3722         sbi->s_stripe = ext4_get_stripe_size(sbi);
3723         sbi->s_max_writeback_mb_bump = 128;
3724         sbi->s_extent_max_zeroout_kb = 32;
3725
3726         /* Register extent status tree shrinker */
3727         ext4_es_register_shrinker(sb);
3728
3729         /*
3730          * set up enough so that it can read an inode
3731          */
3732         if (!test_opt(sb, NOLOAD) &&
3733             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3734                 sb->s_op = &ext4_sops;
3735         else
3736                 sb->s_op = &ext4_nojournal_sops;
3737         sb->s_export_op = &ext4_export_ops;
3738         sb->s_xattr = ext4_xattr_handlers;
3739 #ifdef CONFIG_QUOTA
3740         sb->dq_op = &ext4_quota_operations;
3741         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3742                 sb->s_qcop = &ext4_qctl_sysfile_operations;
3743         else
3744                 sb->s_qcop = &ext4_qctl_operations;
3745 #endif
3746         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3747
3748         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3749         mutex_init(&sbi->s_orphan_lock);
3750
3751         sb->s_root = NULL;
3752
3753         needs_recovery = (es->s_last_orphan != 0 ||
3754                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3755                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3756
3757         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3758             !(sb->s_flags & MS_RDONLY))
3759                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3760                         goto failed_mount3;
3761
3762         /*
3763          * The first inode we look at is the journal inode.  Don't try
3764          * root first: it may be modified in the journal!
3765          */
3766         if (!test_opt(sb, NOLOAD) &&
3767             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3768                 if (ext4_load_journal(sb, es, journal_devnum))
3769                         goto failed_mount3;
3770         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3771               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3772                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3773                        "suppressed and not mounted read-only");
3774                 goto failed_mount_wq;
3775         } else {
3776                 clear_opt(sb, DATA_FLAGS);
3777                 sbi->s_journal = NULL;
3778                 needs_recovery = 0;
3779                 goto no_journal;
3780         }
3781
3782         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3783             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3784                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3785                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3786                 goto failed_mount_wq;
3787         }
3788
3789         if (!set_journal_csum_feature_set(sb)) {
3790                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3791                          "feature set");
3792                 goto failed_mount_wq;
3793         }
3794
3795         /* We have now updated the journal if required, so we can
3796          * validate the data journaling mode. */
3797         switch (test_opt(sb, DATA_FLAGS)) {
3798         case 0:
3799                 /* No mode set, assume a default based on the journal
3800                  * capabilities: ORDERED_DATA if the journal can
3801                  * cope, else JOURNAL_DATA
3802                  */
3803                 if (jbd2_journal_check_available_features
3804                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3805                         set_opt(sb, ORDERED_DATA);
3806                 else
3807                         set_opt(sb, JOURNAL_DATA);
3808                 break;
3809
3810         case EXT4_MOUNT_ORDERED_DATA:
3811         case EXT4_MOUNT_WRITEBACK_DATA:
3812                 if (!jbd2_journal_check_available_features
3813                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3814                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3815                                "requested data journaling mode");
3816                         goto failed_mount_wq;
3817                 }
3818         default:
3819                 break;
3820         }
3821         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3822
3823         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3824
3825         /*
3826          * The journal may have updated the bg summary counts, so we
3827          * need to update the global counters.
3828          */
3829         percpu_counter_set(&sbi->s_freeclusters_counter,
3830                            ext4_count_free_clusters(sb));
3831         percpu_counter_set(&sbi->s_freeinodes_counter,
3832                            ext4_count_free_inodes(sb));
3833         percpu_counter_set(&sbi->s_dirs_counter,
3834                            ext4_count_dirs(sb));
3835         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3836
3837 no_journal:
3838         /*
3839          * Get the # of file system overhead blocks from the
3840          * superblock if present.
3841          */
3842         if (es->s_overhead_clusters)
3843                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3844         else {
3845                 err = ext4_calculate_overhead(sb);
3846                 if (err)
3847                         goto failed_mount_wq;
3848         }
3849
3850         /*
3851          * The maximum number of concurrent works can be high and
3852          * concurrency isn't really necessary.  Limit it to 1.
3853          */
3854         EXT4_SB(sb)->dio_unwritten_wq =
3855                 alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3856         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3857                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3858                 ret = -ENOMEM;
3859                 goto failed_mount_wq;
3860         }
3861
3862         /*
3863          * The jbd2_journal_load will have done any necessary log recovery,
3864          * so we can safely mount the rest of the filesystem now.
3865          */
3866
3867         root = ext4_iget(sb, EXT4_ROOT_INO);
3868         if (IS_ERR(root)) {
3869                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3870                 ret = PTR_ERR(root);
3871                 root = NULL;
3872                 goto failed_mount4;
3873         }
3874         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3875                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3876                 iput(root);
3877                 goto failed_mount4;
3878         }
3879         sb->s_root = d_make_root(root);
3880         if (!sb->s_root) {
3881                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3882                 ret = -ENOMEM;
3883                 goto failed_mount4;
3884         }
3885
3886         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3887                 sb->s_flags |= MS_RDONLY;
3888
3889         /* determine the minimum size of new large inodes, if present */
3890         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3891                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3892                                                      EXT4_GOOD_OLD_INODE_SIZE;
3893                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3894                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3895                         if (sbi->s_want_extra_isize <
3896                             le16_to_cpu(es->s_want_extra_isize))
3897                                 sbi->s_want_extra_isize =
3898                                         le16_to_cpu(es->s_want_extra_isize);
3899                         if (sbi->s_want_extra_isize <
3900                             le16_to_cpu(es->s_min_extra_isize))
3901                                 sbi->s_want_extra_isize =
3902                                         le16_to_cpu(es->s_min_extra_isize);
3903                 }
3904         }
3905         /* Check if enough inode space is available */
3906         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3907                                                         sbi->s_inode_size) {
3908                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3909                                                        EXT4_GOOD_OLD_INODE_SIZE;
3910                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3911                          "available");
3912         }
3913
3914         err = ext4_setup_system_zone(sb);
3915         if (err) {
3916                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3917                          "zone (%d)", err);
3918                 goto failed_mount4a;
3919         }
3920
3921         ext4_ext_init(sb);
3922         err = ext4_mb_init(sb);
3923         if (err) {
3924                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3925                          err);
3926                 goto failed_mount5;
3927         }
3928
3929         err = ext4_register_li_request(sb, first_not_zeroed);
3930         if (err)
3931                 goto failed_mount6;
3932
3933         sbi->s_kobj.kset = ext4_kset;
3934         init_completion(&sbi->s_kobj_unregister);
3935         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3936                                    "%s", sb->s_id);
3937         if (err)
3938                 goto failed_mount7;
3939
3940 #ifdef CONFIG_QUOTA
3941         /* Enable quota usage during mount. */
3942         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
3943             !(sb->s_flags & MS_RDONLY)) {
3944                 err = ext4_enable_quotas(sb);
3945                 if (err)
3946                         goto failed_mount8;
3947         }
3948 #endif  /* CONFIG_QUOTA */
3949
3950         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3951         ext4_orphan_cleanup(sb, es);
3952         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3953         if (needs_recovery) {
3954                 ext4_msg(sb, KERN_INFO, "recovery complete");
3955                 ext4_mark_recovery_complete(sb, es);
3956         }
3957         if (EXT4_SB(sb)->s_journal) {
3958                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3959                         descr = " journalled data mode";
3960                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3961                         descr = " ordered data mode";
3962                 else
3963                         descr = " writeback data mode";
3964         } else
3965                 descr = "out journal";
3966
3967         if (test_opt(sb, DISCARD)) {
3968                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
3969                 if (!blk_queue_discard(q))
3970                         ext4_msg(sb, KERN_WARNING,
3971                                  "mounting with \"discard\" option, but "
3972                                  "the device does not support discard");
3973         }
3974
3975         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3976                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3977                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3978
3979         if (es->s_error_count)
3980                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3981
3982         kfree(orig_data);
3983         return 0;
3984
3985 cantfind_ext4:
3986         if (!silent)
3987                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3988         goto failed_mount;
3989
3990 #ifdef CONFIG_QUOTA
3991 failed_mount8:
3992         kobject_del(&sbi->s_kobj);
3993 #endif
3994 failed_mount7:
3995         ext4_unregister_li_request(sb);
3996 failed_mount6:
3997         ext4_mb_release(sb);
3998 failed_mount5:
3999         ext4_ext_release(sb);
4000         ext4_release_system_zone(sb);
4001 failed_mount4a:
4002         dput(sb->s_root);
4003         sb->s_root = NULL;
4004 failed_mount4:
4005         ext4_msg(sb, KERN_ERR, "mount failed");
4006         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4007 failed_mount_wq:
4008         if (sbi->s_journal) {
4009                 jbd2_journal_destroy(sbi->s_journal);
4010                 sbi->s_journal = NULL;
4011         }
4012 failed_mount3:
4013         del_timer(&sbi->s_err_report);
4014         if (sbi->s_flex_groups)
4015                 ext4_kvfree(sbi->s_flex_groups);
4016         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4017         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4018         percpu_counter_destroy(&sbi->s_dirs_counter);
4019         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4020         percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4021         if (sbi->s_mmp_tsk)
4022                 kthread_stop(sbi->s_mmp_tsk);
4023 failed_mount2:
4024         for (i = 0; i < db_count; i++)
4025                 brelse(sbi->s_group_desc[i]);
4026         ext4_kvfree(sbi->s_group_desc);
4027 failed_mount:
4028         if (sbi->s_chksum_driver)
4029                 crypto_free_shash(sbi->s_chksum_driver);
4030         if (sbi->s_proc) {
4031                 remove_proc_entry("options", sbi->s_proc);
4032                 remove_proc_entry(sb->s_id, ext4_proc_root);
4033         }
4034 #ifdef CONFIG_QUOTA
4035         for (i = 0; i < MAXQUOTAS; i++)
4036                 kfree(sbi->s_qf_names[i]);
4037 #endif
4038         ext4_blkdev_remove(sbi);
4039         brelse(bh);
4040 out_fail:
4041         sb->s_fs_info = NULL;
4042         kfree(sbi->s_blockgroup_lock);
4043         kfree(sbi);
4044 out_free_orig:
4045         kfree(orig_data);
4046         return err ? err : ret;
4047 }
4048
4049 /*
4050  * Setup any per-fs journal parameters now.  We'll do this both on
4051  * initial mount, once the journal has been initialised but before we've
4052  * done any recovery; and again on any subsequent remount.
4053  */
4054 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4055 {
4056         struct ext4_sb_info *sbi = EXT4_SB(sb);
4057
4058         journal->j_commit_interval = sbi->s_commit_interval;
4059         journal->j_min_batch_time = sbi->s_min_batch_time;
4060         journal->j_max_batch_time = sbi->s_max_batch_time;
4061
4062         write_lock(&journal->j_state_lock);
4063         if (test_opt(sb, BARRIER))
4064                 journal->j_flags |= JBD2_BARRIER;
4065         else
4066                 journal->j_flags &= ~JBD2_BARRIER;
4067         if (test_opt(sb, DATA_ERR_ABORT))
4068                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4069         else
4070                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4071         write_unlock(&journal->j_state_lock);
4072 }
4073
4074 static journal_t *ext4_get_journal(struct super_block *sb,
4075                                    unsigned int journal_inum)
4076 {
4077         struct inode *journal_inode;
4078         journal_t *journal;
4079
4080         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4081
4082         /* First, test for the existence of a valid inode on disk.  Bad
4083          * things happen if we iget() an unused inode, as the subsequent
4084          * iput() will try to delete it. */
4085
4086         journal_inode = ext4_iget(sb, journal_inum);
4087         if (IS_ERR(journal_inode)) {
4088                 ext4_msg(sb, KERN_ERR, "no journal found");
4089                 return NULL;
4090         }
4091         if (!journal_inode->i_nlink) {
4092                 make_bad_inode(journal_inode);
4093                 iput(journal_inode);
4094                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4095                 return NULL;
4096         }
4097
4098         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4099                   journal_inode, journal_inode->i_size);
4100         if (!S_ISREG(journal_inode->i_mode)) {
4101                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4102                 iput(journal_inode);
4103                 return NULL;
4104         }
4105
4106         journal = jbd2_journal_init_inode(journal_inode);
4107         if (!journal) {
4108                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4109                 iput(journal_inode);
4110                 return NULL;
4111         }
4112         journal->j_private = sb;
4113         ext4_init_journal_params(sb, journal);
4114         return journal;
4115 }
4116
4117 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4118                                        dev_t j_dev)
4119 {
4120         struct buffer_head *bh;
4121         journal_t *journal;
4122         ext4_fsblk_t start;
4123         ext4_fsblk_t len;
4124         int hblock, blocksize;
4125         ext4_fsblk_t sb_block;
4126         unsigned long offset;
4127         struct ext4_super_block *es;
4128         struct block_device *bdev;
4129
4130         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4131
4132         bdev = ext4_blkdev_get(j_dev, sb);
4133         if (bdev == NULL)
4134                 return NULL;
4135
4136         blocksize = sb->s_blocksize;
4137         hblock = bdev_logical_block_size(bdev);
4138         if (blocksize < hblock) {
4139                 ext4_msg(sb, KERN_ERR,
4140                         "blocksize too small for journal device");
4141                 goto out_bdev;
4142         }
4143
4144         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4145         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4146         set_blocksize(bdev, blocksize);
4147         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4148                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4149                        "external journal");
4150                 goto out_bdev;
4151         }
4152
4153         es = (struct ext4_super_block *) (bh->b_data + offset);
4154         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4155             !(le32_to_cpu(es->s_feature_incompat) &
4156               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4157                 ext4_msg(sb, KERN_ERR, "external journal has "
4158                                         "bad superblock");
4159                 brelse(bh);
4160                 goto out_bdev;
4161         }
4162
4163         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4164                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4165                 brelse(bh);
4166                 goto out_bdev;
4167         }
4168
4169         len = ext4_blocks_count(es);
4170         start = sb_block + 1;
4171         brelse(bh);     /* we're done with the superblock */
4172
4173         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4174                                         start, len, blocksize);
4175         if (!journal) {
4176                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4177                 goto out_bdev;
4178         }
4179         journal->j_private = sb;
4180         ll_rw_block(READ, 1, &journal->j_sb_buffer);
4181         wait_on_buffer(journal->j_sb_buffer);
4182         if (!buffer_uptodate(journal->j_sb_buffer)) {
4183                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4184                 goto out_journal;
4185         }
4186         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4187                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4188                                         "user (unsupported) - %d",
4189                         be32_to_cpu(journal->j_superblock->s_nr_users));
4190                 goto out_journal;
4191         }
4192         EXT4_SB(sb)->journal_bdev = bdev;
4193         ext4_init_journal_params(sb, journal);
4194         return journal;
4195
4196 out_journal:
4197         jbd2_journal_destroy(journal);
4198 out_bdev:
4199         ext4_blkdev_put(bdev);
4200         return NULL;
4201 }
4202
4203 static int ext4_load_journal(struct super_block *sb,
4204                              struct ext4_super_block *es,
4205                              unsigned long journal_devnum)
4206 {
4207         journal_t *journal;
4208         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4209         dev_t journal_dev;
4210         int err = 0;
4211         int really_read_only;
4212
4213         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4214
4215         if (journal_devnum &&
4216             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4217                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4218                         "numbers have changed");
4219                 journal_dev = new_decode_dev(journal_devnum);
4220         } else
4221                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4222
4223         really_read_only = bdev_read_only(sb->s_bdev);
4224
4225         /*
4226          * Are we loading a blank journal or performing recovery after a
4227          * crash?  For recovery, we need to check in advance whether we
4228          * can get read-write access to the device.
4229          */
4230         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4231                 if (sb->s_flags & MS_RDONLY) {
4232                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4233                                         "required on readonly filesystem");
4234                         if (really_read_only) {
4235                                 ext4_msg(sb, KERN_ERR, "write access "
4236                                         "unavailable, cannot proceed");
4237                                 return -EROFS;
4238                         }
4239                         ext4_msg(sb, KERN_INFO, "write access will "
4240                                "be enabled during recovery");
4241                 }
4242         }
4243
4244         if (journal_inum && journal_dev) {
4245                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4246                        "and inode journals!");
4247                 return -EINVAL;
4248         }
4249
4250         if (journal_inum) {
4251                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4252                         return -EINVAL;
4253         } else {
4254                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4255                         return -EINVAL;
4256         }
4257
4258         if (!(journal->j_flags & JBD2_BARRIER))
4259                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4260
4261         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4262                 err = jbd2_journal_wipe(journal, !really_read_only);
4263         if (!err) {
4264                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4265                 if (save)
4266                         memcpy(save, ((char *) es) +
4267                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4268                 err = jbd2_journal_load(journal);
4269                 if (save)
4270                         memcpy(((char *) es) + EXT4_S_ERR_START,
4271                                save, EXT4_S_ERR_LEN);
4272                 kfree(save);
4273         }
4274
4275         if (err) {
4276                 ext4_msg(sb, KERN_ERR, "error loading journal");
4277                 jbd2_journal_destroy(journal);
4278                 return err;
4279         }
4280
4281         EXT4_SB(sb)->s_journal = journal;
4282         ext4_clear_journal_err(sb, es);
4283
4284         if (!really_read_only && journal_devnum &&
4285             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4286                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4287
4288                 /* Make sure we flush the recovery flag to disk. */
4289                 ext4_commit_super(sb, 1);
4290         }
4291
4292         return 0;
4293 }
4294
4295 static int ext4_commit_super(struct super_block *sb, int sync)
4296 {
4297         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4298         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4299         int error = 0;
4300
4301         if (!sbh || block_device_ejected(sb))
4302                 return error;
4303         if (buffer_write_io_error(sbh)) {
4304                 /*
4305                  * Oh, dear.  A previous attempt to write the
4306                  * superblock failed.  This could happen because the
4307                  * USB device was yanked out.  Or it could happen to
4308                  * be a transient write error and maybe the block will
4309                  * be remapped.  Nothing we can do but to retry the
4310                  * write and hope for the best.
4311                  */
4312                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4313                        "superblock detected");
4314                 clear_buffer_write_io_error(sbh);
4315                 set_buffer_uptodate(sbh);
4316         }
4317         /*
4318          * If the file system is mounted read-only, don't update the
4319          * superblock write time.  This avoids updating the superblock
4320          * write time when we are mounting the root file system
4321          * read/only but we need to replay the journal; at that point,
4322          * for people who are east of GMT and who make their clock
4323          * tick in localtime for Windows bug-for-bug compatibility,
4324          * the clock is set in the future, and this will cause e2fsck
4325          * to complain and force a full file system check.
4326          */
4327         if (!(sb->s_flags & MS_RDONLY))
4328                 es->s_wtime = cpu_to_le32(get_seconds());
4329         if (sb->s_bdev->bd_part)
4330                 es->s_kbytes_written =
4331                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4332                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4333                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4334         else
4335                 es->s_kbytes_written =
4336                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4337         ext4_free_blocks_count_set(es,
4338                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4339                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4340         es->s_free_inodes_count =
4341                 cpu_to_le32(percpu_counter_sum_positive(
4342                                 &EXT4_SB(sb)->s_freeinodes_counter));
4343         BUFFER_TRACE(sbh, "marking dirty");
4344         ext4_superblock_csum_set(sb);
4345         mark_buffer_dirty(sbh);
4346         if (sync) {
4347                 error = sync_dirty_buffer(sbh);
4348                 if (error)
4349                         return error;
4350
4351                 error = buffer_write_io_error(sbh);
4352                 if (error) {
4353                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4354                                "superblock");
4355                         clear_buffer_write_io_error(sbh);
4356                         set_buffer_uptodate(sbh);
4357                 }
4358         }
4359         return error;
4360 }
4361
4362 /*
4363  * Have we just finished recovery?  If so, and if we are mounting (or
4364  * remounting) the filesystem readonly, then we will end up with a
4365  * consistent fs on disk.  Record that fact.
4366  */
4367 static void ext4_mark_recovery_complete(struct super_block *sb,
4368                                         struct ext4_super_block *es)
4369 {
4370         journal_t *journal = EXT4_SB(sb)->s_journal;
4371
4372         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4373                 BUG_ON(journal != NULL);
4374                 return;
4375         }
4376         jbd2_journal_lock_updates(journal);
4377         if (jbd2_journal_flush(journal) < 0)
4378                 goto out;
4379
4380         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4381             sb->s_flags & MS_RDONLY) {
4382                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4383                 ext4_commit_super(sb, 1);
4384         }
4385
4386 out:
4387         jbd2_journal_unlock_updates(journal);
4388 }
4389
4390 /*
4391  * If we are mounting (or read-write remounting) a filesystem whose journal
4392  * has recorded an error from a previous lifetime, move that error to the
4393  * main filesystem now.
4394  */
4395 static void ext4_clear_journal_err(struct super_block *sb,
4396                                    struct ext4_super_block *es)
4397 {
4398         journal_t *journal;
4399         int j_errno;
4400         const char *errstr;
4401
4402         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4403
4404         journal = EXT4_SB(sb)->s_journal;
4405
4406         /*
4407          * Now check for any error status which may have been recorded in the
4408          * journal by a prior ext4_error() or ext4_abort()
4409          */
4410
4411         j_errno = jbd2_journal_errno(journal);
4412         if (j_errno) {
4413                 char nbuf[16];
4414
4415                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4416                 ext4_warning(sb, "Filesystem error recorded "
4417                              "from previous mount: %s", errstr);
4418                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4419
4420                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4421                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4422                 ext4_commit_super(sb, 1);
4423
4424                 jbd2_journal_clear_err(journal);
4425                 jbd2_journal_update_sb_errno(journal);
4426         }
4427 }
4428
4429 /*
4430  * Force the running and committing transactions to commit,
4431  * and wait on the commit.
4432  */
4433 int ext4_force_commit(struct super_block *sb)
4434 {
4435         journal_t *journal;
4436
4437         if (sb->s_flags & MS_RDONLY)
4438                 return 0;
4439
4440         journal = EXT4_SB(sb)->s_journal;
4441         return ext4_journal_force_commit(journal);
4442 }
4443
4444 static int ext4_sync_fs(struct super_block *sb, int wait)
4445 {
4446         int ret = 0;
4447         tid_t target;
4448         struct ext4_sb_info *sbi = EXT4_SB(sb);
4449
4450         trace_ext4_sync_fs(sb, wait);
4451         flush_workqueue(sbi->dio_unwritten_wq);
4452         /*
4453          * Writeback quota in non-journalled quota case - journalled quota has
4454          * no dirty dquots
4455          */
4456         dquot_writeback_dquots(sb, -1);
4457         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4458                 if (wait)
4459                         jbd2_log_wait_commit(sbi->s_journal, target);
4460         }
4461         return ret;
4462 }
4463
4464 /*
4465  * LVM calls this function before a (read-only) snapshot is created.  This
4466  * gives us a chance to flush the journal completely and mark the fs clean.
4467  *
4468  * Note that only this function cannot bring a filesystem to be in a clean
4469  * state independently. It relies on upper layer to stop all data & metadata
4470  * modifications.
4471  */
4472 static int ext4_freeze(struct super_block *sb)
4473 {
4474         int error = 0;
4475         journal_t *journal;
4476
4477         if (sb->s_flags & MS_RDONLY)
4478                 return 0;
4479
4480         journal = EXT4_SB(sb)->s_journal;
4481
4482         /* Now we set up the journal barrier. */
4483         jbd2_journal_lock_updates(journal);
4484
4485         /*
4486          * Don't clear the needs_recovery flag if we failed to flush
4487          * the journal.
4488          */
4489         error = jbd2_journal_flush(journal);
4490         if (error < 0)
4491                 goto out;
4492
4493         /* Journal blocked and flushed, clear needs_recovery flag. */
4494         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4495         error = ext4_commit_super(sb, 1);
4496 out:
4497         /* we rely on upper layer to stop further updates */
4498         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4499         return error;
4500 }
4501
4502 /*
4503  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4504  * flag here, even though the filesystem is not technically dirty yet.
4505  */
4506 static int ext4_unfreeze(struct super_block *sb)
4507 {
4508         if (sb->s_flags & MS_RDONLY)
4509                 return 0;
4510
4511         /* Reset the needs_recovery flag before the fs is unlocked. */
4512         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4513         ext4_commit_super(sb, 1);
4514         return 0;
4515 }
4516
4517 /*
4518  * Structure to save mount options for ext4_remount's benefit
4519  */
4520 struct ext4_mount_options {
4521         unsigned long s_mount_opt;
4522         unsigned long s_mount_opt2;
4523         kuid_t s_resuid;
4524         kgid_t s_resgid;
4525         unsigned long s_commit_interval;
4526         u32 s_min_batch_time, s_max_batch_time;
4527 #ifdef CONFIG_QUOTA
4528         int s_jquota_fmt;
4529         char *s_qf_names[MAXQUOTAS];
4530 #endif
4531 };
4532
4533 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4534 {
4535         struct ext4_super_block *es;
4536         struct ext4_sb_info *sbi = EXT4_SB(sb);
4537         unsigned long old_sb_flags;
4538         struct ext4_mount_options old_opts;
4539         int enable_quota = 0;
4540         ext4_group_t g;
4541         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4542         int err = 0;
4543 #ifdef CONFIG_QUOTA
4544         int i, j;
4545 #endif
4546         char *orig_data = kstrdup(data, GFP_KERNEL);
4547
4548         /* Store the original options */
4549         old_sb_flags = sb->s_flags;
4550         old_opts.s_mount_opt = sbi->s_mount_opt;
4551         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4552         old_opts.s_resuid = sbi->s_resuid;
4553         old_opts.s_resgid = sbi->s_resgid;
4554         old_opts.s_commit_interval = sbi->s_commit_interval;
4555         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4556         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4557 #ifdef CONFIG_QUOTA
4558         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4559         for (i = 0; i < MAXQUOTAS; i++)
4560                 if (sbi->s_qf_names[i]) {
4561                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4562                                                          GFP_KERNEL);
4563                         if (!old_opts.s_qf_names[i]) {
4564                                 for (j = 0; j < i; j++)
4565                                         kfree(old_opts.s_qf_names[j]);
4566                                 kfree(orig_data);
4567                                 return -ENOMEM;
4568                         }
4569                 } else
4570                         old_opts.s_qf_names[i] = NULL;
4571 #endif
4572         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4573                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4574
4575         /*
4576          * Allow the "check" option to be passed as a remount option.
4577          */
4578         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4579                 err = -EINVAL;
4580                 goto restore_opts;
4581         }
4582
4583         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4584                 ext4_abort(sb, "Abort forced by user");
4585
4586         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4587                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4588
4589         es = sbi->s_es;
4590
4591         if (sbi->s_journal) {
4592                 ext4_init_journal_params(sb, sbi->s_journal);
4593                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4594         }
4595
4596         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4597                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4598                         err = -EROFS;
4599                         goto restore_opts;
4600                 }
4601
4602                 if (*flags & MS_RDONLY) {
4603                         err = dquot_suspend(sb, -1);
4604                         if (err < 0)
4605                                 goto restore_opts;
4606
4607                         /*
4608                          * First of all, the unconditional stuff we have to do
4609                          * to disable replay of the journal when we next remount
4610                          */
4611                         sb->s_flags |= MS_RDONLY;
4612
4613                         /*
4614                          * OK, test if we are remounting a valid rw partition
4615                          * readonly, and if so set the rdonly flag and then
4616                          * mark the partition as valid again.
4617                          */
4618                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4619                             (sbi->s_mount_state & EXT4_VALID_FS))
4620                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4621
4622                         if (sbi->s_journal)
4623                                 ext4_mark_recovery_complete(sb, es);
4624                 } else {
4625                         /* Make sure we can mount this feature set readwrite */
4626                         if (!ext4_feature_set_ok(sb, 0)) {
4627                                 err = -EROFS;
4628                                 goto restore_opts;
4629                         }
4630                         /*
4631                          * Make sure the group descriptor checksums
4632                          * are sane.  If they aren't, refuse to remount r/w.
4633                          */
4634                         for (g = 0; g < sbi->s_groups_count; g++) {
4635                                 struct ext4_group_desc *gdp =
4636                                         ext4_get_group_desc(sb, g, NULL);
4637
4638                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4639                                         ext4_msg(sb, KERN_ERR,
4640                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4641                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4642                                                le16_to_cpu(gdp->bg_checksum));
4643                                         err = -EINVAL;
4644                                         goto restore_opts;
4645                                 }
4646                         }
4647
4648                         /*
4649                          * If we have an unprocessed orphan list hanging
4650                          * around from a previously readonly bdev mount,
4651                          * require a full umount/remount for now.
4652                          */
4653                         if (es->s_last_orphan) {
4654                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4655                                        "remount RDWR because of unprocessed "
4656                                        "orphan inode list.  Please "
4657                                        "umount/remount instead");
4658                                 err = -EINVAL;
4659                                 goto restore_opts;
4660                         }
4661
4662                         /*
4663                          * Mounting a RDONLY partition read-write, so reread
4664                          * and store the current valid flag.  (It may have
4665                          * been changed by e2fsck since we originally mounted
4666                          * the partition.)
4667                          */
4668                         if (sbi->s_journal)
4669                                 ext4_clear_journal_err(sb, es);
4670                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4671                         if (!ext4_setup_super(sb, es, 0))
4672                                 sb->s_flags &= ~MS_RDONLY;
4673                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4674                                                      EXT4_FEATURE_INCOMPAT_MMP))
4675                                 if (ext4_multi_mount_protect(sb,
4676                                                 le64_to_cpu(es->s_mmp_block))) {
4677                                         err = -EROFS;
4678                                         goto restore_opts;
4679                                 }
4680                         enable_quota = 1;
4681                 }
4682         }
4683
4684         /*
4685          * Reinitialize lazy itable initialization thread based on
4686          * current settings
4687          */
4688         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4689                 ext4_unregister_li_request(sb);
4690         else {
4691                 ext4_group_t first_not_zeroed;
4692                 first_not_zeroed = ext4_has_uninit_itable(sb);
4693                 ext4_register_li_request(sb, first_not_zeroed);
4694         }
4695
4696         ext4_setup_system_zone(sb);
4697         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4698                 ext4_commit_super(sb, 1);
4699
4700 #ifdef CONFIG_QUOTA
4701         /* Release old quota file names */
4702         for (i = 0; i < MAXQUOTAS; i++)
4703                 kfree(old_opts.s_qf_names[i]);
4704         if (enable_quota) {
4705                 if (sb_any_quota_suspended(sb))
4706                         dquot_resume(sb, -1);
4707                 else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4708                                         EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4709                         err = ext4_enable_quotas(sb);
4710                         if (err)
4711                                 goto restore_opts;
4712                 }
4713         }
4714 #endif
4715
4716         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4717         kfree(orig_data);
4718         return 0;
4719
4720 restore_opts:
4721         sb->s_flags = old_sb_flags;
4722         sbi->s_mount_opt = old_opts.s_mount_opt;
4723         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4724         sbi->s_resuid = old_opts.s_resuid;
4725         sbi->s_resgid = old_opts.s_resgid;
4726         sbi->s_commit_interval = old_opts.s_commit_interval;
4727         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4728         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4729 #ifdef CONFIG_QUOTA
4730         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4731         for (i = 0; i < MAXQUOTAS; i++) {
4732                 kfree(sbi->s_qf_names[i]);
4733                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4734         }
4735 #endif
4736         kfree(orig_data);
4737         return err;
4738 }
4739
4740 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4741 {
4742         struct super_block *sb = dentry->d_sb;
4743         struct ext4_sb_info *sbi = EXT4_SB(sb);
4744         struct ext4_super_block *es = sbi->s_es;
4745         ext4_fsblk_t overhead = 0;
4746         u64 fsid;
4747         s64 bfree;
4748
4749         if (!test_opt(sb, MINIX_DF))
4750                 overhead = sbi->s_overhead;
4751
4752         buf->f_type = EXT4_SUPER_MAGIC;
4753         buf->f_bsize = sb->s_blocksize;
4754         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4755         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4756                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4757         /* prevent underflow in case that few free space is available */
4758         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4759         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4760         if (buf->f_bfree < ext4_r_blocks_count(es))
4761                 buf->f_bavail = 0;
4762         buf->f_files = le32_to_cpu(es->s_inodes_count);
4763         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4764         buf->f_namelen = EXT4_NAME_LEN;
4765         fsid = le64_to_cpup((void *)es->s_uuid) ^
4766                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4767         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4768         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4769
4770         return 0;
4771 }
4772
4773 /* Helper function for writing quotas on sync - we need to start transaction
4774  * before quota file is locked for write. Otherwise the are possible deadlocks:
4775  * Process 1                         Process 2
4776  * ext4_create()                     quota_sync()
4777  *   jbd2_journal_start()                  write_dquot()
4778  *   dquot_initialize()                         down(dqio_mutex)
4779  *     down(dqio_mutex)                    jbd2_journal_start()
4780  *
4781  */
4782
4783 #ifdef CONFIG_QUOTA
4784
4785 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4786 {
4787         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4788 }
4789
4790 static int ext4_write_dquot(struct dquot *dquot)
4791 {
4792         int ret, err;
4793         handle_t *handle;
4794         struct inode *inode;
4795
4796         inode = dquot_to_inode(dquot);
4797         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4798                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4799         if (IS_ERR(handle))
4800                 return PTR_ERR(handle);
4801         ret = dquot_commit(dquot);
4802         err = ext4_journal_stop(handle);
4803         if (!ret)
4804                 ret = err;
4805         return ret;
4806 }
4807
4808 static int ext4_acquire_dquot(struct dquot *dquot)
4809 {
4810         int ret, err;
4811         handle_t *handle;
4812
4813         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4814                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4815         if (IS_ERR(handle))
4816                 return PTR_ERR(handle);
4817         ret = dquot_acquire(dquot);
4818         err = ext4_journal_stop(handle);
4819         if (!ret)
4820                 ret = err;
4821         return ret;
4822 }
4823
4824 static int ext4_release_dquot(struct dquot *dquot)
4825 {
4826         int ret, err;
4827         handle_t *handle;
4828
4829         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4830                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4831         if (IS_ERR(handle)) {
4832                 /* Release dquot anyway to avoid endless cycle in dqput() */
4833                 dquot_release(dquot);
4834                 return PTR_ERR(handle);
4835         }
4836         ret = dquot_release(dquot);
4837         err = ext4_journal_stop(handle);
4838         if (!ret)
4839                 ret = err;
4840         return ret;
4841 }
4842
4843 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4844 {
4845         struct super_block *sb = dquot->dq_sb;
4846         struct ext4_sb_info *sbi = EXT4_SB(sb);
4847
4848         /* Are we journaling quotas? */
4849         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
4850             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4851                 dquot_mark_dquot_dirty(dquot);
4852                 return ext4_write_dquot(dquot);
4853         } else {
4854                 return dquot_mark_dquot_dirty(dquot);
4855         }
4856 }
4857
4858 static int ext4_write_info(struct super_block *sb, int type)
4859 {
4860         int ret, err;
4861         handle_t *handle;
4862
4863         /* Data block + inode block */
4864         handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
4865         if (IS_ERR(handle))
4866                 return PTR_ERR(handle);
4867         ret = dquot_commit_info(sb, type);
4868         err = ext4_journal_stop(handle);
4869         if (!ret)
4870                 ret = err;
4871         return ret;
4872 }
4873
4874 /*
4875  * Turn on quotas during mount time - we need to find
4876  * the quota file and such...
4877  */
4878 static int ext4_quota_on_mount(struct super_block *sb, int type)
4879 {
4880         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4881                                         EXT4_SB(sb)->s_jquota_fmt, type);
4882 }
4883
4884 /*
4885  * Standard function to be called on quota_on
4886  */
4887 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4888                          struct path *path)
4889 {
4890         int err;
4891
4892         if (!test_opt(sb, QUOTA))
4893                 return -EINVAL;
4894
4895         /* Quotafile not on the same filesystem? */
4896         if (path->dentry->d_sb != sb)
4897                 return -EXDEV;
4898         /* Journaling quota? */
4899         if (EXT4_SB(sb)->s_qf_names[type]) {
4900                 /* Quotafile not in fs root? */
4901                 if (path->dentry->d_parent != sb->s_root)
4902                         ext4_msg(sb, KERN_WARNING,
4903                                 "Quota file not on filesystem root. "
4904                                 "Journaled quota will not work");
4905         }
4906
4907         /*
4908          * When we journal data on quota file, we have to flush journal to see
4909          * all updates to the file when we bypass pagecache...
4910          */
4911         if (EXT4_SB(sb)->s_journal &&
4912             ext4_should_journal_data(path->dentry->d_inode)) {
4913                 /*
4914                  * We don't need to lock updates but journal_flush() could
4915                  * otherwise be livelocked...
4916                  */
4917                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4918                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4919                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4920                 if (err)
4921                         return err;
4922         }
4923
4924         return dquot_quota_on(sb, type, format_id, path);
4925 }
4926
4927 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4928                              unsigned int flags)
4929 {
4930         int err;
4931         struct inode *qf_inode;
4932         unsigned long qf_inums[MAXQUOTAS] = {
4933                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4934                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4935         };
4936
4937         BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4938
4939         if (!qf_inums[type])
4940                 return -EPERM;
4941
4942         qf_inode = ext4_iget(sb, qf_inums[type]);
4943         if (IS_ERR(qf_inode)) {
4944                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4945                 return PTR_ERR(qf_inode);
4946         }
4947
4948         err = dquot_enable(qf_inode, type, format_id, flags);
4949         iput(qf_inode);
4950
4951         return err;
4952 }
4953
4954 /* Enable usage tracking for all quota types. */
4955 static int ext4_enable_quotas(struct super_block *sb)
4956 {
4957         int type, err = 0;
4958         unsigned long qf_inums[MAXQUOTAS] = {
4959                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4960                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4961         };
4962
4963         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4964         for (type = 0; type < MAXQUOTAS; type++) {
4965                 if (qf_inums[type]) {
4966                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4967                                                 DQUOT_USAGE_ENABLED);
4968                         if (err) {
4969                                 ext4_warning(sb,
4970                                         "Failed to enable quota tracking "
4971                                         "(type=%d, err=%d). Please run "
4972                                         "e2fsck to fix.", type, err);
4973                                 return err;
4974                         }
4975                 }
4976         }
4977         return 0;
4978 }
4979
4980 /*
4981  * quota_on function that is used when QUOTA feature is set.
4982  */
4983 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
4984                                  int format_id)
4985 {
4986         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4987                 return -EINVAL;
4988
4989         /*
4990          * USAGE was enabled at mount time. Only need to enable LIMITS now.
4991          */
4992         return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
4993 }
4994
4995 static int ext4_quota_off(struct super_block *sb, int type)
4996 {
4997         struct inode *inode = sb_dqopt(sb)->files[type];
4998         handle_t *handle;
4999
5000         /* Force all delayed allocation blocks to be allocated.
5001          * Caller already holds s_umount sem */
5002         if (test_opt(sb, DELALLOC))
5003                 sync_filesystem(sb);
5004
5005         if (!inode)
5006                 goto out;
5007
5008         /* Update modification times of quota files when userspace can
5009          * start looking at them */
5010         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5011         if (IS_ERR(handle))
5012                 goto out;
5013         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5014         ext4_mark_inode_dirty(handle, inode);
5015         ext4_journal_stop(handle);
5016
5017 out:
5018         return dquot_quota_off(sb, type);
5019 }
5020
5021 /*
5022  * quota_off function that is used when QUOTA feature is set.
5023  */
5024 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5025 {
5026         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5027                 return -EINVAL;
5028
5029         /* Disable only the limits. */
5030         return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5031 }
5032
5033 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5034  * acquiring the locks... As quota files are never truncated and quota code
5035  * itself serializes the operations (and no one else should touch the files)
5036  * we don't have to be afraid of races */
5037 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5038                                size_t len, loff_t off)
5039 {
5040         struct inode *inode = sb_dqopt(sb)->files[type];
5041         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5042         int err = 0;
5043         int offset = off & (sb->s_blocksize - 1);
5044         int tocopy;
5045         size_t toread;
5046         struct buffer_head *bh;
5047         loff_t i_size = i_size_read(inode);
5048
5049         if (off > i_size)
5050                 return 0;
5051         if (off+len > i_size)
5052                 len = i_size-off;
5053         toread = len;
5054         while (toread > 0) {
5055                 tocopy = sb->s_blocksize - offset < toread ?
5056                                 sb->s_blocksize - offset : toread;
5057                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5058                 if (err)
5059                         return err;
5060                 if (!bh)        /* A hole? */
5061                         memset(data, 0, tocopy);
5062                 else
5063                         memcpy(data, bh->b_data+offset, tocopy);
5064                 brelse(bh);
5065                 offset = 0;
5066                 toread -= tocopy;
5067                 data += tocopy;
5068                 blk++;
5069         }
5070         return len;
5071 }
5072
5073 /* Write to quotafile (we know the transaction is already started and has
5074  * enough credits) */
5075 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5076                                 const char *data, size_t len, loff_t off)
5077 {
5078         struct inode *inode = sb_dqopt(sb)->files[type];
5079         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5080         int err = 0;
5081         int offset = off & (sb->s_blocksize - 1);
5082         struct buffer_head *bh;
5083         handle_t *handle = journal_current_handle();
5084
5085         if (EXT4_SB(sb)->s_journal && !handle) {
5086                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5087                         " cancelled because transaction is not started",
5088                         (unsigned long long)off, (unsigned long long)len);
5089                 return -EIO;
5090         }
5091         /*
5092          * Since we account only one data block in transaction credits,
5093          * then it is impossible to cross a block boundary.
5094          */
5095         if (sb->s_blocksize - offset < len) {
5096                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5097                         " cancelled because not block aligned",
5098                         (unsigned long long)off, (unsigned long long)len);
5099                 return -EIO;
5100         }
5101
5102         bh = ext4_bread(handle, inode, blk, 1, &err);
5103         if (!bh)
5104                 goto out;
5105         err = ext4_journal_get_write_access(handle, bh);
5106         if (err) {
5107                 brelse(bh);
5108                 goto out;
5109         }
5110         lock_buffer(bh);
5111         memcpy(bh->b_data+offset, data, len);
5112         flush_dcache_page(bh->b_page);
5113         unlock_buffer(bh);
5114         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5115         brelse(bh);
5116 out:
5117         if (err)
5118                 return err;
5119         if (inode->i_size < off + len) {
5120                 i_size_write(inode, off + len);
5121                 EXT4_I(inode)->i_disksize = inode->i_size;
5122                 ext4_mark_inode_dirty(handle, inode);
5123         }
5124         return len;
5125 }
5126
5127 #endif
5128
5129 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5130                        const char *dev_name, void *data)
5131 {
5132         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5133 }
5134
5135 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5136 static inline void register_as_ext2(void)
5137 {
5138         int err = register_filesystem(&ext2_fs_type);
5139         if (err)
5140                 printk(KERN_WARNING
5141                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5142 }
5143
5144 static inline void unregister_as_ext2(void)
5145 {
5146         unregister_filesystem(&ext2_fs_type);
5147 }
5148
5149 static inline int ext2_feature_set_ok(struct super_block *sb)
5150 {
5151         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5152                 return 0;
5153         if (sb->s_flags & MS_RDONLY)
5154                 return 1;
5155         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5156                 return 0;
5157         return 1;
5158 }
5159 #else
5160 static inline void register_as_ext2(void) { }
5161 static inline void unregister_as_ext2(void) { }
5162 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5163 #endif
5164
5165 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5166 static inline void register_as_ext3(void)
5167 {
5168         int err = register_filesystem(&ext3_fs_type);
5169         if (err)
5170                 printk(KERN_WARNING
5171                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5172 }
5173
5174 static inline void unregister_as_ext3(void)
5175 {
5176         unregister_filesystem(&ext3_fs_type);
5177 }
5178
5179 static inline int ext3_feature_set_ok(struct super_block *sb)
5180 {
5181         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5182                 return 0;
5183         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5184                 return 0;
5185         if (sb->s_flags & MS_RDONLY)
5186                 return 1;
5187         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5188                 return 0;
5189         return 1;
5190 }
5191 #else
5192 static inline void register_as_ext3(void) { }
5193 static inline void unregister_as_ext3(void) { }
5194 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5195 #endif
5196
5197 static struct file_system_type ext4_fs_type = {
5198         .owner          = THIS_MODULE,
5199         .name           = "ext4",
5200         .mount          = ext4_mount,
5201         .kill_sb        = kill_block_super,
5202         .fs_flags       = FS_REQUIRES_DEV,
5203 };
5204 MODULE_ALIAS_FS("ext4");
5205
5206 static int __init ext4_init_feat_adverts(void)
5207 {
5208         struct ext4_features *ef;
5209         int ret = -ENOMEM;
5210
5211         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5212         if (!ef)
5213                 goto out;
5214
5215         ef->f_kobj.kset = ext4_kset;
5216         init_completion(&ef->f_kobj_unregister);
5217         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5218                                    "features");
5219         if (ret) {
5220                 kfree(ef);
5221                 goto out;
5222         }
5223
5224         ext4_feat = ef;
5225         ret = 0;
5226 out:
5227         return ret;
5228 }
5229
5230 static void ext4_exit_feat_adverts(void)
5231 {
5232         kobject_put(&ext4_feat->f_kobj);
5233         wait_for_completion(&ext4_feat->f_kobj_unregister);
5234         kfree(ext4_feat);
5235 }
5236
5237 /* Shared across all ext4 file systems */
5238 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5239 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5240
5241 static int __init ext4_init_fs(void)
5242 {
5243         int i, err;
5244
5245         ext4_li_info = NULL;
5246         mutex_init(&ext4_li_mtx);
5247
5248         /* Build-time check for flags consistency */
5249         ext4_check_flag_values();
5250
5251         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5252                 mutex_init(&ext4__aio_mutex[i]);
5253                 init_waitqueue_head(&ext4__ioend_wq[i]);
5254         }
5255
5256         err = ext4_init_es();
5257         if (err)
5258                 return err;
5259
5260         err = ext4_init_pageio();
5261         if (err)
5262                 goto out7;
5263
5264         err = ext4_init_system_zone();
5265         if (err)
5266                 goto out6;
5267         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5268         if (!ext4_kset) {
5269                 err = -ENOMEM;
5270                 goto out5;
5271         }
5272         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5273
5274         err = ext4_init_feat_adverts();
5275         if (err)
5276                 goto out4;
5277
5278         err = ext4_init_mballoc();
5279         if (err)
5280                 goto out3;
5281
5282         err = ext4_init_xattr();
5283         if (err)
5284                 goto out2;
5285         err = init_inodecache();
5286         if (err)
5287                 goto out1;
5288         register_as_ext3();
5289         register_as_ext2();
5290         err = register_filesystem(&ext4_fs_type);
5291         if (err)
5292                 goto out;
5293
5294         return 0;
5295 out:
5296         unregister_as_ext2();
5297         unregister_as_ext3();
5298         destroy_inodecache();
5299 out1:
5300         ext4_exit_xattr();
5301 out2:
5302         ext4_exit_mballoc();
5303 out3:
5304         ext4_exit_feat_adverts();
5305 out4:
5306         if (ext4_proc_root)
5307                 remove_proc_entry("fs/ext4", NULL);
5308         kset_unregister(ext4_kset);
5309 out5:
5310         ext4_exit_system_zone();
5311 out6:
5312         ext4_exit_pageio();
5313 out7:
5314         ext4_exit_es();
5315
5316         return err;
5317 }
5318
5319 static void __exit ext4_exit_fs(void)
5320 {
5321         ext4_destroy_lazyinit_thread();
5322         unregister_as_ext2();
5323         unregister_as_ext3();
5324         unregister_filesystem(&ext4_fs_type);
5325         destroy_inodecache();
5326         ext4_exit_xattr();
5327         ext4_exit_mballoc();
5328         ext4_exit_feat_adverts();
5329         remove_proc_entry("fs/ext4", NULL);
5330         kset_unregister(ext4_kset);
5331         ext4_exit_system_zone();
5332         ext4_exit_pageio();
5333 }
5334
5335 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5336 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5337 MODULE_LICENSE("GPL");
5338 module_init(ext4_init_fs)
5339 module_exit(ext4_exit_fs)